Here we go again---too rich fuel trim troubles never end!

[cparke]

Ok, I'm still trying to solve this problem, and I'm just not getting anywhere no matter what I do. So frustrating!

Basic problem, for those of you who haven't been following, ECU sees air/fuel mixture as being too rich, sets negative lambdas for multiplicative trim, eventually lambda go over -15% to -25% and the fault code is thrown. Bank 1 always richer than bank 2, however both grow together.

New parts installed trying to fix---MAF, fuel pressure regulator, small vacuum lines, fuel injectors swapped between banks and 1 new fuel injector installed on bank 1.

Spark plug inspection---plugs are 4 months old, problem has existed all 4 months, electrodes are white.

Swapped the O2 sensors, but bank 1 is still more richer than bank 2. O2 sensor elements are mostly snow white. However, idle/additive fuel trim on both banks is now positive now for the first time ever! (currently, bank 1 trim is additive 7.8% and multiplicative -14.2%).

I just don't know what to make of all of this. The spark plugs say I'm running rich by their white-ness, but the O2 sensors say I'm not by their white-ness. Bad O2 sensors are supposed cause the system to think it is running too lean, not too rich like mine are. Swapping O2 sensors was supposed to make bank 2 become the richer one if the O2 sensors are the actual cause, but that is not what is happening. Inconsistencies, inconsistencies! I just don't know what to do next!

Please, any further ideas, now is the time to throw them out there.

[Affinitive]

Sorry, kinda stayed out of the tech sections lately. Been insanely busy and haven't had time for my long winded posts. I do remember seeing something a while back about swapping injectors.... and stayed out of it for, well, ... a number of reasons.....

Anywho,...only the multi trims are whacky....eh??? Yes yes yes, we all like whacky trim.....

Let me guess, it's an AHA motor..right??? Better yet, still has the original purple top injectors in it too???

Also, the plugs turning white means the actuall combustion is too lean...just like the O2's. Don't mean to be a prick saying that, but whoever told you that plugs will turn white from rich combustion while the O2's turn white is a a bit backwards there. They both will turn white form excessive combustion temps resulting from lean fuel mixtures.
Your trim numbers also prove lean mixtures.

Let's back to the basics here. On the throttle housing, there is a seal sealing the plastic intake duct to the throttle housing. How's that seal??? Before you tell me it's OK, keep in mind I've had to change many of them because they will cause false air leaks. Mainly so when driving under load (as in multi trim) but hardly any when idling since the air flow through the intake plumbing leading to the throttle is fairly minimal. Which also leads into the next question of Crankcase Venting. Is the crankcase vent plumbing OK??? Especially where it connects to the plastic intake duct as as I mentioned earlier. Let me guess, you still have the original Jet Suction Pump on this thing???

The question marks are in place for a reason, soooooo ......

Again, not to be prick or nothing.....but why and who told you to swap O2's???

C

[cparke]

Sorry, kinda stayed out of the tech sections lately. Been insanely busy and haven't had time for my long winded posts. I do remember seeing something a while back about swapping injectors.... and stayed out of it for, well, ... a number of reasons.....

Anywho,...only the multi trims are whacky....eh??? Yes yes yes, we all like whacky trim.....

Hello Affinitive,

Thank you so much for stepping up with some new thoughts on what could be remaining for me to check. I extremely appreciate it!

Answers to your questions:

Yes --- AHA motor

Yes---original purple top injectors in it, except presently I have installed 1 new injector bank 1, the new injector has a red top. I am contemplating returning the purple injector once I get this is fiasco resolved. I also put a new fuel pressure regulator on the rail and changed the small vacuum lines leading to it. No changes. I have not actually connected a fuel pressure guage to the rail, however.

Colors---I read that white on spark plug electrodes indicates carbon deposits, and normal coloring should be tan-brown. But of course, the plugs are only 4 months old so their proper coloration may not have set in yet. O2 sensors color I thought white meant antifreeze or silicon contamination, though I'm not sure what the normal coloration is. It was good to take them out and look at them anyway.

The O2 sensors are the originals, I had to cut the wire straps to get them out. I swapped them because I want to see if one or both are giving false high voltage readings, perhaps due to some contamination blocking their ability to see oxygen. Overall, I have been trying to make bank 2 trim more severe than bank 1 to identify the cause of this problem, but nothing I've swapped (injectors, O2 sensors) has had any effect, suggesting that these parts are not bad.

My trim numbers seem to prove to me that the computer is making the engine run lean, perhaps improperly, because it thinks that the exhaust is rich. Only multiplicative trims have been a problem, correct. Bank 1 is always more negative than Bank 2, but both do tend to creep up together and, at the extreme, Bank 2 does go out of spec. too. It does take a few days or a week or more before the DTC comes up, and there does seem to be some intermittent spikes in the readings that are partially responsible for the long learning processing.

Plastic intake duct--- I've taken this off a few times now, most recently in order to swap the O2 sensors (yes, I did remove and re-install them from under the hood, not under the car). The seal is a little bit soft rubber, and it does come off the plastic duct without much difficulty. I've never done an intake pressure test to check that, yes. The intake duct does have a little bit of oil in it from the oil venting line, I have to wipe that off each time before re-installing the duct, and I suppose that some oil does get under the seal maybe. The car also does have a small oil leak, probably through the valve cover gaskets, I've been told that this oil leak could not be the cause of my fuel trim problems.

The car does not have a turbo engine, so my understanding has been that if the intake has a leak, the result would be UNMETERED AIR (not false air), resulting in the O2 sensors and ECU seeing a TOO LEAN mixture and adding fuel to compensate (positive trim values) and possibly throwing a TOO LEAN DTC. I have the reverse situation, false air would require metered intake air to get blown out the system after the MAF, resulting in less air reaching the combustion chamber than expected. And it would affect both banks approximately equally too, wouldn't it? The only thing interesting about this thought of yours is that after my swap of the O2 sensors this weekend and re-installing the intake duct, I am now getting, for the first time, somewhat (but within spec.) lean results on additive trims on both banks, but the multiplicative remain rich and too negative on bank 1 as before.

I'm not sure what you mean by the Jet Suction Pump, do you mean the Secondary Air Injection pump? If not, what is the thing you are talking about and where is it approximately? My secondary air injection pump does seem to be blowing air up under the hood, but it still does blow air up the plastic piping correct too. Supposedly a leak there should not affect trims.

Knowing all these things, I don't understand why I haven't found the cause of this problem, but hopefully you can shed some further light on these facts to bring me closer to finding the cause. Thanks.


CP

[Affinitive]

LOL

Sorry, I know it's not funny. Fuel Trim is a very good and "easy" concept. Though surprisingly tough to truly understand. We'll get into it later, but let's set theory and principle aside for now as well as some of the minor details on the car. Having idle and load trim values (lambda control) makes things more confusing. Though you are on the right track, just weeving around a few misplaced cones so to say and maybe even starting to run opposite of the rest of the race. No offense, just in good fun, been there myself many times over the years. Again, fuel trim (lambda control) is tricky to understand truly. so don't beat yourself up.

The pic above is that Jet Suction Pump. Part number 058 133 753B which is still available aftermarket (like ECS.....) as the "B" number eventhough the OE part has been updated to a "D" and of course more expensive but still cheap considering. Think of it as basicly like a PCV Valve. Causes a whole mess of problems and very misunderstood part. Most people don't even know what it is and does. Most noteably known to cause excessive oil consumption and leaks. Should be replaced every tune up but usually doesn't since so few understand that little gadget.

Don't have too much time to get all long winded (more so than I already am) but from this point on, go ahead and replace the seal for the intake duct to the throttle housing and this jet suction pump. I'm sure you've noticed it mounted right next to the throttle. Also make sure all the plastic vent tubes/pipes are ok. Actually the main breather hose connecting both valve covers with the little cannister where the rubber hose connects the suction pump to the canister should also be replaced if hasn't been already. Surprised it hasn't broken considering how often the intake duct has been pulled and how briddle the plastic gets over time (props to you for the skillful hands and patience).

As a rule of thumb, the intake duct should fit fairly snug when the seal is good and gets real loose when the seal goes bad over time. Quickest way to check is with a smoke machine..............

Long story short, I bet ya 20 bucks that the seal and jet suction pump are causing your issues. We'll discuss the details later. If you don't believe me, you can consider it a cheap gamble at this point, especially considering your given position. TRUST ME.

C

[Affinitive]

Ohh yeah
unmetered and false air leak referr to the same thing, just different choice of words.

C

[cparke]

The pic above is that Jet Suction Pump. Part number 058 133 753B which is still available aftermarket (like ECS.....) as the "B" number eventhough the OE part has been updated to a "D" and of course more expensive but still cheap considering. Think of it as basicly like a PCV Valve. Causes a whole mess of problems and very misunderstood part. Most people don't even know what it is and does. Most noteably known to cause excessive oil consumption and leaks. Should be replaced every tune up but usually doesn't since so few understand that little gadget.

Hi Affinitive,

These are truly unique ideas on what is actually causing my problem!

The seal for the intake duct to the throttle housing is simple to change, and I guess I need to visit by Audi/VW dealer and get a new one.

Yes, I've seen that so-called jet suction pump, looks mostly like a merge contraption for the vacuum system, I've ordered it and will fight later this week with how to get it on. Always was afraid of it, very hard to reach.

How do you recommend I make sure all the plastic vent tubes/pipes are ok? They look visibly okay, but if they are cracked somewhere, it might be hard to see. Can I do a vacuum test on them (how do you cap them?)?

Actually the main breather hose connecting both valve covers with the little cannister where the rubber hose connects the suction pump to the canister should also be replaced if hasn't been already. Surprised it hasn't broken considering how often the intake duct has been pulled and how briddle the plastic gets over time (props to you for the skillful hands and patience)

Thanks for your compliments, I work very slow because I don't entirely know what I'm doing and want to avoid breaking or losing anything (though I am screwing up a little bit nevertheless but getting better at this game). I'm not sure what you mean by the "main breather hose", however. These two plastic lines from the valve covers for oil venting do indeed merge into a rubber canister which seems to also be connected to the vacuum system but then also runs down to the intake duct (how the hell that whole system works is a mystery to me). Are we talking about the plastic hose section that connects the canister to the intake duct and which I have to disconnect when I take off the intake duct?

Much appreciation for your ideas, guess I've got to just keep on trying to find the leak, seems like the consensus is that it must be a leak somewhere at this point.

[Affinitive]

yeah, the main breather hose being the one going form the front of the passenger side valve cover crossing over and running to the back connecting to the driver side valve cover and down to the intake duct. Like you've seen, it has the little canister in it and then a short little rubber hose connecting it to the suction pump, the angled fitting on the suction pump. The plastic tubing, you wana look for it being broken. Minor cracks wont be too much of an issue. Just in case, part number 078 103 224R. ECS or the like should also have that but may be expensivce to ship considering it's size. Can't fold it up or nothing.

As for changing the suction pump itself. Unhook the electrical connectors to the solenoids mounted on that plastic plate sitting on the top. then unhook a couple of vacuum lines as needed and move the whole platic plate to the side to gain access to the suction pump. the plastic plate is secured with 3 bolts, one of which goes into the intake duct. When you get that plate moved aside, you'll also notice a short stubby and fairly large diameter vacuum hose on the passenger of the throttle with a tiny "T" fitting. Check/replace that stubby hose as well. I'm prtty sure it's ok at this point since it would produce a major vacuum leak but better get it while there. The suction pump is really easy to change once the plat is moved aside. Just be careful to finagle it out of the big vacuum hose it's mounted into on the manifold. You'll be fine, don't worry.

Also forgot to mention about the duct seal. It's "directional", so to say. It has to be "clocked" or "indexed" if you will. You'll see what I mean when you see the sections cut out of it. You'll figure it out, just make sure to it sits on there nice and flat. you'll see. Once you replace it and think about the air flow characteristics form idle to driving and such, it'll make perfect sense.

C

[Affinitive]

Ohh yeah, the pump gadget actually has 2 little rubber diaphrams inside to regulate crankcase venting proportional to manifold vacuum and such. Actually it by itself could cause fuel trim faults to set.............

Trust me, all this will make sense and I'll still put my 20 bucks on the table if need be,....well..................

C

[cparke]

Also forgot to mention about the duct seal. It's "directional", so to say. It has to be "clocked" or "indexed" if you will. You'll see what I mean when you see the sections cut out of it.C

I'm don't understand that, you're right, but I trust that I will once I get the seal.

Keep you're $20, I probably owe it to you whether these things fix the problem or not (which is the way all the mechanics around where I live charge for doing things---only stupid looks are free).

Thank you so much!

[cparke]

Hello Affinitive,

Okay, I got the parts you suggested and installed them tonight. Results, of course, are not what I expected, as you will see below.

I also checked out the PVC breather hose... definitely it is sealed tight and definitely no leaks. There is also another short PVC line connected to it right after the connection to the driver's side valve cover and before the connection to the purge valve (suction pump) which runs down and connects into the back of the intake manifold under the throttle body----this line I couldn't check because I couldn't get it off the manifold because you have to take out the throttle body to get a good grip on the connection, but the line looked pretty good to me. Cutting off the factory crimped clamps on the purge valve connection was lots of fun! (yeah, it must have been original)

I also tried to check the valve covers for air leaks by pumping air into them---I could not maintain any pressure. Is that normal? Ditto for the the two lines going into the manifold for the purge valve and the other line described above for the oil venting directly into the manifold---could not maintain pressure for either of them too. Is this okay?

After reconnecting everything, clearing the computer, and starting the car, it has a lot of trouble idling and almost stalls several times, then we start to get a smell of sulfur. I take the car out for a local drive to let it warm up so the O2 sensors can give some readings to learn from. The car is now running severely rich, even at idle! -25% on both banks and too rich fault code on both banks throws almost immediately. The O2 sensor readings in measuring block 33 no longer move up and down like they used to, but are steadily at high voltage (I believe the ECU is actually supposed to report the average, something it didn't seem to be doing previously), and only slowly do they creep down to .435 volt once the engine is turned off.

I've disconnected the battery for overnight, just to make sure the ECU is fully cleared of all previous learned values. But I'm not very hopeful everything will just run right tomorrow.

Let's suppose I actually had two fuel trim problems at the same time, one causing a lean trim and one causing a rich trim. They tended to cancel each other out, but of course the rich trim problem was stronger and that's what I saw. Now I fixed the lean problem with your excellent advice, but the too rich is much more pronounced. Where do I go from here? What the hell is left to be causing this? I'm sure I reconnected everything correctly. Fuel pressure? (even though there is a new fuel pressure regulator installed)? Even if excess pressure is the problem causing too rich, what am I going to be able to do about it? EVAP canister?

I'm not even sure it is safe for the O2 sensors and catalytic converter to drive this car when it is running so rich. What more is there to do?

Thanks for your further thoughts.
CP

[cparke]

UPDATE:

Okay, after re-powering up the ECU and doing throttle body adaptation, car is running somewhat like it was before, except it adjusts trims to their high negative values (currently -21.6% B1 and -18.0% B2) rather quickly and begins throwing the too rich fault on B1 within the first drive. O2 sensor voltages are moving around once again.

So, it seem this purge valve and intake duct gasket did not really solve the too rich condition. I don't know what to do once again. I'd like to pull the GIAC chip (which appears to be sitting in a socket on the ECU board), but I don't know what direction the writing on the OEM chip is supposed to face. Other than fuel pressure and a world of problems that much be involved there, a haywire ECU is the only other thing I can think of.

Any more great ideas out there?

[Affinitive]

LOL (again, I know it's not funny). As canievng as it seems, that all sounds about right. The fact that now the problem seems much more severe, so to say, is a good thing (depending on how you look at it..I guess).

Anywho, now we move onto the coolant temp sensor, part # 078 919 501B, and the EVAP Purge Valve, part # 077 133 517C. Dealer only type of deal on the temp sensor. They should have dozens in stock. Get the little O-Ring too. They should also have plenty of the purge valve as well but the OE bosch valves will be available through several sources.

Just to varify, what all fault codes exactly are setting. I'm assuming you're getting 16556, 16559, 17537, and 17545 or any combination of the four. has it ever set any faults pertaining to the coolant temp sensor or EVAP purge malfunctions of any sort. Being an older car like this, probably not on the coolant temp sensor and maybe on the evap purge.

As for the O2 voltage slowly creepin down after shuttng off, that's because the sensors are getting saturated with fuel. After everything is fixed up, they'll probably clean up after a good drive.

Starting to see where and how all this is going??? Sorry for the delay here.

C

[Affinitive]

Ohh yeah, the coolant temp sensor, wait till everything is cold and leave the cap on the resevoir. When you take the sonsor out, it will only spill a little coolant....surprisingly.

Also just out of curiosity, is the gas tank close to being full???

C

[cparke]

Hi Affinity,

I changed the engine coolant temp. sensor already, and that did not help, but after changing it, it also put the computer into a fit of rage like this jet suction pump (purge valve) did. As I said, after the computer was fully reset in both cases, back to normal (too rich) behavior. The goofy O2 sensor voltage readings, again that all went away in the morning.

The EVAP purge valve---that I haven't changed since the EVAP leak detection pump always passes on the system. However, there was a time a few months ago when I was getting intermittent EVAP large leaks. Guess I should try changing that one too just to be sure. Is there a procedure you recommend to fully discharge the EVAP canister so there is little pressure in the system when I disconnect it to change it?

Here are my ECU readings from Saturday morning after my test drive and setting readiness (engine off):

Saturday,06,September,2008,09:00:24:36581
VCDS Version: Release 805.1
Data version: 20080823

Address 01: Engine
Control Module Part Number: 4D0 907 551 AH
Component and/or Version: 2.8L V6/5V MOTR AT D01
Software Coding: 06251
Work Shop Code: WSC 06335
1 Fault Found:

17535 - Fuel Trim; Bank 1 (Mult): System too Rich
P1127 - 35-10 - - - Intermittent

Readiness: 0000 0000


Saturday,06,September,2008,09:01:57:36581
VCDS Version: Release 805.1
Data version: 20080823

Address 01: Engine (4D0 907 551 AH)

09:01:56 Group 000: Engine Status
203 ECT
000 Load
000 RPM
006 T-ang
128 I-air
133 I-lrn
138 O2S1
144 O2S2
122 IO2S1
120 IO2S2

09:01:56 Group 032: O2S control learning values (before Cat. Conv.) [B=Bank S=Sensor]
-4.7 % @idle B1S1 +/-10%
-22.7 % @part B1S1 +/-10%
-6.3 % @idle B2S1 +/-10%
-18.0 % @part B2S1 +/-10%

09:01:56 Group 055: Idle control (@idle) [A=AWD F=FWD]
0 /min Idle Speed 620-740A/+120F
0.00 g/s Idle air ctrl -1.39-+1.39g/s
0.70 g/s Learn value -1.39-+1.39g/s
0000 Op condition 0000=A/0100=F

[cparke]

BTW - the EVAP purge valve part # on my car is 058133459. Are you talking about a different part in the EVAP system?

[Affinitive]

The number you're looking at is the rubber holder/mounting grommet. Take the grommet off the vavlve and you'll see the number and Bosch number will 0 280 142 308.

So you got the coolant temp sensor already.....HUH...OK. I guess maybe I missed it in the beginning of the thread....sorry about that.

As for the leak detection pump test. I find that to be almost useless to be honest when actaully checking EVAP malfunctions. really serves more for setting readiness and vehicle self testing strategy. When it comes to evap malfunction faults and leak faults, 99 out of 100 times I end up having to replace the purge valve. And generally the leak tests using vagcom will pass just fine while in the shop. Send the car out and at some point it acts again. For several years now I pretty much always replace the purge valves at the first signs of trouble and to date everyone has been cured. The cause is the mechanical parts of the valve. It's basicly the "High Wear" part of the system. Sometimes they stick open/closed or whatever. I used to take the time to actually cycle the valves several times until I could catch them acting up. Now I just replace and have never had to take one back out as misdiagnosed. Even had to replace one in a 05 model last week with barely ver 50K on the car because it was already starting to set intermittant leak faults. These things are a common problem, especially for Audi's and VW's. By this age and mileage, you have to remember that valve will have cycled open and closed hundreds of thousands of times if not over a million.

Considering it also had intermittant large leak faults in the past, I gurantee you it's bad. I also wouldn't be surprised if the EVAP cannister is saturated at this point. That will probably clear up once the EVAP system functions properly again. No need to "discharge " anything. If you want, you could take the gas cap off but no need really.

Yup defintely the purge valve next.

C

[Affinitive]

Also thinking here. Going on a real stretch here, but it is possible that the fuel return line could be pinched anywhere underneath the car somewhere.

What is the actuall fuel pressure???

C

[cparke]

Also thinking here. Going on a real stretch here, but it is possible that the fuel return line could be pinched anywhere underneath the car somewhere.

What is the actuall fuel pressure???

C

Fuel pressure I have not tested. that is one of the few tests that I have not had done yet. Instead, I changed the FPR and hoped that would solve any fuel pressure issues. I'd have to buy a $40 pressure tester and then do the messy work of disconnecting the fuel rail to check the fuel pressure. Reving the engine with that thing connected scares me too. And as I said before, what would I do to fix it if it was too high?

My EVAP purge valve still has the factory crimped clamps on it, so it is guaranteed still the original part. I'm looking into getting the part and crossing my fingers again for n-teenth time.

[Affinitive]

Well the only thing that cause fuel pressure to be too high would be a faulty regualtor or a pinched return line. Checking pressure can be a hassle on one of these without the proper adaptor. You're probably fine there. Have your ever bottomed out on something or run over something that could have damaged and pinched a fuel line. Very unlikely for a number of reasons.

I suppose something to consider, maybe a decent idea to unhook the the vacuum hose to the valve (the engine side) and cap or pinch the hose and see what happens to the trim numbers. Maybe even unhook the hose on the other side and start the engine and see if vacuum is being pulled through the valve with the electrical connector unhooked to make sure it won't start cycling. Obviously not a good idea to drive around with the tank/canister side open into the engine bay.

As for the factory crimps. I myself use those clamps as well and honestly I would not be surprised if the car is already on it's 2nd or 3rd purge valve.

Yup, do the purge valve.

C

[cparke]

I suppose something to consider, maybe a decent idea to unhook the the vacuum hose to the valve (the engine side) and cap or pinch the hose and see what happens to the trim numbers. Maybe even unhook the hose on the other side and start the engine and see if vacuum is being pulled through the valve with the electrical connector unhooked to make sure it won't start cycling. Obviously not a good idea to drive around with the tank/canister side open into the engine bay.

Ok, I got the $100 EVAP purge valve today and changed it. There was no pressure discernable inside the lines on either side of the EVAP purge valve as I disconnected the old one. Cleared the ECU fault codes and started the engine. Again, the car is in "fit of rage" fuel trim mood, and as the O2 sensors warm up it becomes apparent they are "saturated" (steady at higher voltage). Park the car back in the garage and disconnect the battery for one hour for a full ECU reset to take place. In the meantime, I'm testing my old EVAP purge valve and I find it does open and close correctly and hold pressure, and the new EVAP purge valve also clicks like it should.

1 hour later, I re-power up the ECU and run output diagnostic test mode (DTM mode where the fuel pump runs with the engine off). I'm not sure if this is normal or not, but in the line from engine to EVAP purge valve I can feel something in the hose pulsing it (probably not vacuum, as the engine isn't running), but I feel nothing happening on the other side (canister-side) of the valve. Is that normal? I can feel movement also in the fuel incoming and return lines. Electrical tests with an LED while DTM is running also show the purge valve is getting the power it needs to switch on and off correctly. I take the car for a drive with the purge valve disconnected, O2 sensor live voltages and lambda values seem to suggest that the car is still running rich, but as a fault has been thrown for the open electrical line to the purge valve, no fuel trim learning takes place. At least my O2 sensor voltages are now moving again like they should. I reconnect the purge valve, test drive, and set readiness. Fuel trims learn to between -10% and -20%, seems like the same old problem is still there (after tomorrow's daily 1 hour of driving, we should be certain of that).

Boo hoo hoo! How long should I give the fuel trims to go normal, proper values if the EVAP canister is just "saturated" as you called it? Could the EVAP canister be in fact broken somehow and causing too much pressure in the fuel system and/or too much fuel vapors released at once? Since the purge valve is closed whenever power is disconnected, if I plug in my old EVAP purge valve to the electrical harness while it is connected to nothing, I can fool the computer to do trim learning while also having a safe blockage on the EVAP line across the new purge valve, but is it safe to do that and would the results be at all informative as to whether EVAP system is my trouble spot?

This car is really getting on my nerves---it feels like I have a gambling problem whenever I try to fix it, making me feel sorry each time that I even tried. I also have experienced the ECU fuel trim system's fit of rage (O2 sensor saturation you called it) on the car three times now after changing these parts: The ECT, the jet suction pump & intake gasket, and now the EVAP purge valve. In each case, I don't understand how the ECU even detected that something was changed, unless all these parts were bad! (and noteably, there was no such fit of rage when the MAF was changed).

Other than changing the ECU (which I am doing next), is there anything else you can suggest to check or do at this point before I just have to give up?

[cparke]

My short list of remaining (some perhaps far-fetched) ideas. My engine appears to run fine if not for this CEL. Not sure which of these could be responsible for my too rich condition, need opinions on each's likelihood and how to best test each:

1) EVAP charcoal canister permanently saturated (block off the purge valve? Is that safe?).
2) ECU's GIAC chip (change ECU).
3) Intake Air Temp (IAT) Sensor (remove sensor and blow hot and cold air on it)
4) Throttle Position Sensor (just watch the %'s?)
5) Fuel pressure sensor (is there one? How does ECU know when to purge the EVAP?)
6) Valve leaks (intake and/or exhaust) (compression/leak-down testing)
7) Excessive crankcase blow-by

[Affinitive]

I definitely would not just block off the evap purge line.
Besides the chip, those other things by themselves would never cause such extreme issues. Well, I suppose the intake air temp could if it falsely showing somethinglike -40 degrees, but you would be getting faults since coolant temp on a cold start would correspond to that. If the charcoal canister is practicly full of fuel, it can take a while, if it will, to "clear out", and you want to make sure the fuel level is not full. The evap purging will happen as much as possible once operating temp is reached and should be cycling constantly while of idling if left idling for a long period. Letting the thing idle a long time will certainly help clear out a saturated canister. That's something I would consider doing and see what trim numbers are at after a good drive also. Do you have access to a known good ECM to temporarily swap out???

C

[cparke]

I installed a stock ECU in my car tonight. Car continues to run as usual. No change in the too rich condition. Guess the original ECU and GIAC chip weren't the problem after all.

Also I did my home-brewed EVAP system test---unplugged the elctrical wiring from the new purge valve so that it will stay closed at all times, plugged in the electrical wiring to the old purge valve connected nothing so that no fault is thrown for purge valve circuit open, took off the gas cap, and took the car for a drive to do some learning. Got a fault code for EVAP large leak (the missing gas cap), but otherwise fuel trim learning did take place. Still running rich with the EVAP system effectively disabled. Guess EVAP system isn't the problem after all.

Checked the vacuum line to the fuel pressure regulator for vacuum. There is some light vacuum in the line; I can put my finger on the end of the hose and block the line without any pain or difficulty pulling it off. No fuel leaks from the newly installed fuel pressure regulator. Guess FPR still isn't the problem.

Checked the intake air temperature sensor with freeze spray. Was able to get it to read down to -45 celcius I think. Seems to be reading correct ambient temperature the rest of the time. Cleaned the sensor with MAF cleaner anyway. When driving, intake temperature reading seems to be about 3-5 degrees celcius warmer than actual outdoor temperature, though that still may be correct since the airbox and intake hose and duct are warm when the engine is running.

That's about it for what I think that I can check from my short list. Unfortunately, I'm no better off than when I started. This is a really strange problem indeed.

[cparke]

Letting the thing idle a long time will certainly help clear out a saturated canister. That's something I would consider doing and see what trim numbers are at after a good drive also.

Hi Affinitive,

I forgot to mention, I can make the idle/additive fuel trim go too rich also. While it doesn't typically go too rich with normal starting and driving conditions, if you let the car just sit and idle with the O2 sensors heated and fully active, the O2 sensor voltages do go high and the additive trims will go up. So, higher RPM's really aren't necessary to cause the problem. And I never heard of a fuel pump going bad give too much pressure (rather it is usually the reverse, isn't it?).

Clogged fuel return lines slowly pushing up the fuel pressure? Is there a drain-o for fuel lines? Any other brillant ideas?, cause that's my last one I think.

[cparke]

Also, my fuel indicator seems to be periodically reading higher than actual. I thought when the fuel sender goes bad it usually reads lower than actual. Could fuel return back up also explain that?

[cparke]

With the stock ECU now installed, I have more confidence in my ignition timing retard and knock readings. Intermittently while driving this car, knock sensor readings appear at very high numbers (from 5 to 12 is the highest). I've been told in the past that after timing retard of 12, the ECU additionally adds fuel to the mixture provide further retard.

Now, if this intermittent excess timing retard is the reason why the engine increasingly runs rich over time, what does that suggest about what could be wrong with my car to cause the knocking in the first place? (previously, I had been thinking that the knocking was just part of the chipped program, or a side-effect of the fuel cut back strategy from the ECU detecting the rich condition; i.e. the engine is sometimes running lean because too much fuel gets pulled using the previous rich sensor readimg)

[Affinitive]

OK. Soooo I kinda disregarded everything and went back to square one and looked through the original thread you started about this...........I also owe you an appology as I kinda just jumped to the classic text book and pattern failures. Typical stuff I deal with given certain age and mileage issues and focusing too much on all the various little issues, many of which will often times help to mask one another.

The fuel system cleaner/additive basicly correcting one somwhat minor issue and uncovered you headache here. That being overdue injector performance issues pertaining to fuel sediments building up in the injectors and minor carbon deposits on the injector tips and intake runner inline of injector spray and intake valves. Great, got that cleaned up and now a deeper problem has been uncovered.

Then it leads into questions of pressure and such. The pump by itself won't and can't produce too much pressure, so to say. The restriction to flow is what generates pressure. The pump is mechanically limited in how much fuel it can move and as wear and tear takes place, the amount of fuel it can move will decrease. Again though, the restriction to flow is what produces pressure.

I would still like to varify the actuall pressure just to be sure. Though I still don't think that the pressure is actually too high. It's pretty much impossible to develop so much gunk and stuff in the fuel system to clog the return line with a cleaning product to raise the fuel pressure. Also, idle trim numbers would be affected very quickly if it was the case.

Let's also touch briefly on knock regulation. Extra fuel add is not really a measure taken to regulate knock (pre detonation) but rather to correct fuel mixtures and combustion quality which in turns cause excessive knock. Does that make sense. This again is where I have faultered and should have asked more questions to begin with. I would liked to have known, and should have asked more questions, about the "knocking", eventhough it is somewhat expected given the severe mixture problems.

Generally I would also dismiss the difference between the two banks. There's always gonna be a number of variables contributing to minor trim differences between the two banks, which are normal...........But in your case here, lets look into that a bit more. I'd like to pop off both upper timing belt covers real quick and turn the engine to TDC and varify if both the cam jig plates are located properly. By that I mean the two holes in the jig plates wedged onto the front of the cam sprockets being perfectly level with another and to each other. That's assuming you don't have the cam alignment bar. Again, that's with the engine at TDC. Then, or before hand, start the engine and while idling, look at measuring block 090 and see what what the cam deviation is at. in a perfect world they should both be zero, but a couple of degrees -/+ will be acceptable. But I would still like you to look at the timing belt sprockets at TDC even if the cam deviation looks good on in measuring blocks. I mention this because I noticed in your original thread about this issue, I noticed your mileage and couldn't help but think that the timing belt was done not all too long ago. This may or may not lead back into further deatil I mentioned about the injectors. Even further, I'd like to know what cam deviation jumps to during cam adjustment actuation. Measuring block 090 will display wether cam adjustment is turned on or not. Log it if need be.

Look into that for now.

[cparke]

Then, or before hand, start the engine and while idling, look at measuring block 090 and see what what the cam deviation is at. in a perfect world they should both be zero, but a couple of degrees -/+ will be acceptable.

Hi Affinitive,

Thanks for continuing to think about this for me. Measuring block 90 shows bank 1 at 0 during idle and bank 2 at -2 moving occassionally, briefly to +1. Cam adjustment is off. While driving, I could not get the cam adjustment to go on but the adjustment values did move at times, instantly, to +3 on one or both banks. Not sure what that means, but seems to be within spec.

Sounds like I'm going to need somebody professional to look at the timing and fuel pressure at this point. Doesn't seem like there is much else to do. Appreciate your thoughts, of course.


CP

[Affinitive]

HUH

OK

The one bank at 0 is good. The other bank being slightly out is not too much of a concern. The the fluctuation of 3 degrees is concerning. If the fluctuation was only one degree, I wouldn't be concerned at all since minor speed fluctuations will cause the "perception" of the one degree, but 3 degrees. That's a little too wonky for comfort. As far as cam adjustment actuvation, it should be activating fairly frequently even with normal driving. Especially so on an early car car like this. Pretty much anytime the engine RPM's exceed 3000 - 3500 rpm's, the adjustment should be activated and you would/should see a noticeable jump in cam deviation of +16 - +20 degrees. So that's far more than the 3 degrees you mentioned and again, the measuring block will show "on" and the adjustment range will jump very very very quickly. Cam adjustment is either on or off. So there is no "in-between" on that +16 - +20 degree range.

(Damn it.................)

The basic cam timing by itself being slightly wonky is generally not too much of a concern (usually just a sign of someone doing a timing belt job without proper tools or know-how and also a sign of failing cam adjusters as these things get old, but never seen one causing fuel trim faults just because of a little wonky cam timing).
I guess what I'm getting at here is that this is an indication of further mechanical issues. When manifold vacuum gets affected enough by mechanical issues to affect the air flow characteristics of an issue (engine's ability to pump air), then yes, fuel trim faults and problems will start to crop up.

I'd like you to hook up a vacuum gauge to a straigh tmanifold vacuum source, like the FPR vacuum hose. Don't worry about the pressure raising slightly. With the engine idling, let me know what the vacuum gauge reads and wether it shows a steady reading from cold start till warm. Wonky valve timing or valve train issues will affect manifold vacuum. Which again leads to excess ignition knock due to combustion issues.

Again, knowing now that live data (measuring blocks) show some discrepencies (however that's spelled), I would defintely insist on knowing wether a cam alignment bar will fit into place at "Base Timing". And equally important is the question of manifold vacuum. Do you have access to a vacuum gauge??? You could buy one cheap at a parts store if need be.

Is this thing just a gut-less wonder while driving??? Does it idle fairly smooth/well??? Have you ever had idle adaptation faults set eventhough the throttle valve/body was adapted??? When checking the adaptation channel "01", what is the stored value??? Hopefully it is "128" and the actual idle speed is fairly steady within 10 - 15 rpm's of specified. Specified being that of set adaptation value. factory specified speed varies between manual and auto trans. So an adaptation value of "128" will equate to about 680 with manual trans, but about 80 - 100 rpm higher (if 4 AM memory serves me right) with an auto trans. Make sense???

Let me know about the manifold vacuum.

Colin

[Affinitive]

Ohh yeah

I realise this sounds like it's WAAAAYYYY out there in left field, but uhh, would you be able to tell me what the color of the oil pressure switch is???

I ask because the concern of the cam adjustment not seeming to work properly.....possibly. The cam adjusters are moved with engine oil pressure. An AHA engine should have a black colored switch. A white colored switch would be acceptable also.

Again, I know it sounds way out there in left field, but if possible to check easily, then please do.

C

[cparke]

Hi Colin,

Great thoughts, glad to see them still coming. Maybe we are beginning to get at least an indication of what might be wrong.

The one bank at 0 is good. The other bank being slightly out is not too much of a concern. The the fluctuation of 3 degrees is concerning. If the fluctuation was only one degree, I wouldn't be concerned at all since minor speed fluctuations will cause the "perception" of the one degree, but 3 degrees. That's a little too wonky for comfort. As far as cam adjustment actuvation, it should be activating fairly frequently even with normal driving. Especially so on an early car car like this. Pretty much anytime the engine RPM's exceed 3000 - 3500 rpm's, the adjustment should be activated and you would/should see a noticeable jump in cam deviation of +16 - +20 degrees. So that's far more than the 3 degrees you mentioned and again, the measuring block will show "on" and the adjustment range will jump very very very quickly. Cam adjustment is either on or off. So there is no "in-between" on that +16 - +20 degree range.

While driving in 2nd gear, I swear to you, in one sample bank 1 is at 0, in the next one it is 3, and after a few more samples it falls immediately back to 0. On bank 2, I think it even made that jump from -1 or -2 to 3. And I swear I was driving up in the 5000 rpm range and still adjustment never activated and the numbers never went higher than 3. I can post the log if you want to see it.

The basic cam timing by itself being slightly wonky is generally not too much of a concern (usually just a sign of someone doing a timing belt job without proper tools or know-how and also a sign of failing cam adjusters as these things get old, but never seen one causing fuel trim faults just because of a little wonky cam timing). I guess what I'm getting at here is that this is an indication of further mechanical issues. When manifold vacuum gets affected enough by mechanical issues to affect the air flow characteristics of an issue (engine's ability to pump air), then yes, fuel trim faults and problems will start to crop up.

Great, just what I needed to hear... Now maybe we're getting somewhere!

I'd like you to hook up a vacuum gauge to a straigh tmanifold vacuum source, like the FPR vacuum hose. Don't worry about the pressure raising slightly. With the engine idling, let me know what the vacuum gauge reads and wether it shows a steady reading from cold start till warm. Wonky valve timing or valve train issues will affect manifold vacuum. Which again leads to excess ignition knock due to combustion issues.

There is vacuum in the hoses, but I don't have a guage to measure it. I know I can put my finger over the vacuum hose with the engine idling and I only feel slight pressure, and I certainly have no difficulty removing my finger. When I bring the car in tomorrow for a professional analysis, I now know to bring these things to their attention for exactly this kind of examination.

Is this thing just a gut-less wonder while driving??? Does it idle fairly smooth/well??? Have you ever had idle adaptation faults set eventhough the throttle valve/body was adapted??? When checking the adaptation channel "01", what is the stored value??? Hopefully it is "128" and the actual idle speed is fairly steady within 10 - 15 rpm's of specified. Specified being that of set adaptation value. factory specified speed varies between manual and auto trans. So an adaptation value of "128" will equate to about 680 with manual trans, but about 80 - 100 rpm higher (if 4 AM memory serves me right) with an auto trans. Make sense???

The car runs excellent. You cannot discern any engine problems at idle or cruise. Maybe it is a miracle. If not for the CEL, not a clue anything is wrong. Engine adaptation channel 1 is set to 129. I think that is because it is a quattro.

Haven't looked at the oil pressure switch at all. Are you talking about removing it, or just on the outside?

Thanks so much for your thoughts!

[cparke]

Hi Colin,

I figured it would be just as well to throw this log out there at this point anyway. This log is my 2nd gear drive which failed to get Cam Adjustment on at any point. There is some idle in PARK at the end of the log. Something really smells fishy here, huh?


Saturday,13,September,2008,18:48:29
4D0 907 551 AH,,2.8L V6/5V MOTR AT D03

Group A: '090
TIME|Engine RPM/min|Adj ON/OFF|Adj resp Bank1 (-3-6/16-25degKW)|Adj resp Bank2 (-3-6/16-25degKW)
0.01|1200|Cam Ctrl. OFF|0|-1
0.23|1200|Cam Ctrl. OFF|0|-1
0.51|1520|Cam Ctrl. OFF|0|-1
0.78|1680|Cam Ctrl. OFF|0|-1
1.06|1840|Cam Ctrl. OFF|0|-1
1.33|1920|Cam Ctrl. OFF|0|-1
1.61|2040|Cam Ctrl. OFF|0|-1
1.88|2160|Cam Ctrl. OFF|0|-1
2.16|2320|Cam Ctrl. OFF|0|-1
2.43|2320|Cam Ctrl. OFF|0|-1
2.71|1800|Cam Ctrl. OFF|0|-1
2.98|1840|Cam Ctrl. OFF|0|-1
3.26|1960|Cam Ctrl. OFF|0|-1
3.53|2000|Cam Ctrl. OFF|0|-1
3.81|2080|Cam Ctrl. OFF|0|-1
4.08|2080|Cam Ctrl. OFF|0|-1
4.36|2160|Cam Ctrl. OFF|0|-1
4.63|2200|Cam Ctrl. OFF|0|-1
4.91|2240|Cam Ctrl. OFF|0|2
5.18|2320|Cam Ctrl. OFF|0|-1
5.46|2400|Cam Ctrl. OFF|0|-1
5.73|2480|Cam Ctrl. OFF|0|-1
6.01|2560|Cam Ctrl. OFF|0|-1
6.28|2640|Cam Ctrl. OFF|0|-1
6.56|2680|Cam Ctrl. OFF|0|-1
6.83|2720|Cam Ctrl. OFF|0|-1
7.11|2800|Cam Ctrl. OFF|0|-1
7.38|2880|Cam Ctrl. OFF|0|-1
7.66|2960|Cam Ctrl. OFF|0|-1
7.93|3080|Cam Ctrl. OFF|3|-1
8.20|3160|Cam Ctrl. OFF|3|-1
8.48|3240|Cam Ctrl. OFF|3|-1
8.76|3320|Cam Ctrl. OFF|3|-1
9.03|3440|Cam Ctrl. OFF|3|-1
9.31|3520|Cam Ctrl. OFF|0|-1
9.58|3640|Cam Ctrl. OFF|0|-1
9.87|3640|Cam Ctrl. OFF|0|-1
10.14|3640|Cam Ctrl. OFF|0|-1
10.42|3720|Cam Ctrl. OFF|0|-1
10.75|3880|Cam Ctrl. OFF|0|-1
11.01|3840|Cam Ctrl. OFF|0|-1
11.28|3800|Cam Ctrl. OFF|0|-1
11.56|3800|Cam Ctrl. OFF|0|-1
11.84|3760|Cam Ctrl. OFF|0|-1
12.11|3720|Cam Ctrl. OFF|0|-1
12.39|3680|Cam Ctrl. OFF|0|-1
12.66|3640|Cam Ctrl. OFF|0|-1
12.94|3640|Cam Ctrl. OFF|0|-1
13.21|3560|Cam Ctrl. OFF|0|-1
13.49|3560|Cam Ctrl. OFF|0|-1
13.76|3520|Cam Ctrl. OFF|0|-1
14.04|3480|Cam Ctrl. OFF|0|-1
14.31|3440|Cam Ctrl. OFF|0|-1
14.59|3440|Cam Ctrl. OFF|3|-1
14.86|3400|Cam Ctrl. OFF|3|-1
15.14|3360|Cam Ctrl. OFF|3|-1
15.41|3320|Cam Ctrl. OFF|3|-1
15.69|3320|Cam Ctrl. OFF|3|-1
15.96|3280|Cam Ctrl. OFF|3|-1
16.24|3240|Cam Ctrl. OFF|3|-1
16.51|3240|Cam Ctrl. OFF|3|-1
16.84|3200|Cam Ctrl. OFF|3|-1
17.12|3160|Cam Ctrl. OFF|3|-1
17.39|3120|Cam Ctrl. OFF|3|-1
17.67|3120|Cam Ctrl. OFF|0|-1
17.94|3080|Cam Ctrl. OFF|3|-1
18.22|3040|Cam Ctrl. OFF|3|-1
18.49|3040|Cam Ctrl. OFF|0|-1
18.77|3000|Cam Ctrl. OFF|0|-1
19.04|2960|Cam Ctrl. OFF|0|-1
19.32|2960|Cam Ctrl. OFF|0|-1
19.59|2920|Cam Ctrl. OFF|0|-1
19.87|2920|Cam Ctrl. OFF|0|-1
20.14|2880|Cam Ctrl. OFF|0|-1
20.42|2880|Cam Ctrl. OFF|0|-1
20.69|2760|Cam Ctrl. OFF|0|-1
20.97|2680|Cam Ctrl. OFF|0|-1
21.24|2680|Cam Ctrl. OFF|0|0
21.52|2640|Cam Ctrl. OFF|0|0
21.79|2640|Cam Ctrl. OFF|0|0
22.07|2600|Cam Ctrl. OFF|0|0
22.34|2600|Cam Ctrl. OFF|0|0
22.62|2560|Cam Ctrl. OFF|0|0
22.89|2560|Cam Ctrl. OFF|0|0
23.17|2520|Cam Ctrl. OFF|0|0
23.44|2520|Cam Ctrl. OFF|0|0
23.72|2480|Cam Ctrl. OFF|0|0
23.99|2480|Cam Ctrl. OFF|0|-1
24.27|2440|Cam Ctrl. OFF|0|-1
24.55|2440|Cam Ctrl. OFF|0|-1
24.82|2400|Cam Ctrl. OFF|0|-1
25.09|2400|Cam Ctrl. OFF|0|-1
25.37|2360|Cam Ctrl. OFF|0|-1
25.65|2320|Cam Ctrl. OFF|0|0
25.92|2280|Cam Ctrl. OFF|0|0
26.19|2240|Cam Ctrl. OFF|0|0
26.47|2160|Cam Ctrl. OFF|0|0
26.74|2120|Cam Ctrl. OFF|0|0
27.02|2120|Cam Ctrl. OFF|0|0
27.29|2080|Cam Ctrl. OFF|0|0
27.57|2080|Cam Ctrl. OFF|0|0
27.84|2120|Cam Ctrl. OFF|0|0
28.12|2080|Cam Ctrl. OFF|0|0
28.39|2080|Cam Ctrl. OFF|0|0
28.67|2040|Cam Ctrl. OFF|0|0
29.00|2040|Cam Ctrl. OFF|0|0
29.27|2000|Cam Ctrl. OFF|0|0
29.55|2000|Cam Ctrl. OFF|0|0
29.82|1960|Cam Ctrl. OFF|0|0
30.10|1920|Cam Ctrl. OFF|0|0
30.37|1880|Cam Ctrl. OFF|0|0
30.65|1840|Cam Ctrl. OFF|0|0
30.92|1840|Cam Ctrl. OFF|0|0
31.20|1800|Cam Ctrl. OFF|0|0
31.47|1760|Cam Ctrl. OFF|0|0
31.75|1720|Cam Ctrl. OFF|0|0
32.02|1680|Cam Ctrl. OFF|0|0
32.30|1640|Cam Ctrl. OFF|0|0
32.57|1600|Cam Ctrl. OFF|0|0
32.85|1560|Cam Ctrl. OFF|0|0
33.12|1520|Cam Ctrl. OFF|0|0
33.40|1480|Cam Ctrl. OFF|0|0
33.67|1440|Cam Ctrl. OFF|0|0
33.95|1360|Cam Ctrl. OFF|0|0
34.22|1280|Cam Ctrl. OFF|0|0
34.50|1160|Cam Ctrl. OFF|0|0
34.78|1080|Cam Ctrl. OFF|0|0
35.05|1000|Cam Ctrl. OFF|0|0
35.32| 920|Cam Ctrl. OFF|0|0
35.60| 880|Cam Ctrl. OFF|0|0
35.87| 840|Cam Ctrl. OFF|0|0
36.15| 800|Cam Ctrl. OFF|0|0
36.42| 760|Cam Ctrl. OFF|0|0
36.70| 720|Cam Ctrl. OFF|0|0
36.97| 720|Cam Ctrl. OFF|0|0
37.25| 840|Cam Ctrl. OFF|0|0
37.58|1000|Cam Ctrl. OFF|0|0
37.91|1400|Cam Ctrl. OFF|0|0
38.18|1400|Cam Ctrl. OFF|0|0
38.46|1560|Cam Ctrl. OFF|0|0
38.73|1600|Cam Ctrl. OFF|0|0
39.01|1640|Cam Ctrl. OFF|0|0
39.28|1720|Cam Ctrl. OFF|0|0
39.56|1800|Cam Ctrl. OFF|0|0
39.83|1880|Cam Ctrl. OFF|0|0
40.11|1920|Cam Ctrl. OFF|0|0
40.38|2000|Cam Ctrl. OFF|0|0
40.66|2040|Cam Ctrl. OFF|0|0
40.93|2080|Cam Ctrl. OFF|0|0
41.21|2200|Cam Ctrl. OFF|0|0
41.48|2280|Cam Ctrl. OFF|0|0
41.76|2320|Cam Ctrl. OFF|0|0
42.03|2440|Cam Ctrl. OFF|0|0
42.31|2520|Cam Ctrl. OFF|0|0
42.58|2640|Cam Ctrl. OFF|0|0
42.86|2720|Cam Ctrl. OFF|0|0
43.13|2840|Cam Ctrl. OFF|3|0
43.40|2920|Cam Ctrl. OFF|3|0
43.68|3040|Cam Ctrl. OFF|3|0
43.96|3160|Cam Ctrl. OFF|3|0
44.23|3280|Cam Ctrl. OFF|3|0
44.50|3360|Cam Ctrl. OFF|3|0
44.78|3480|Cam Ctrl. OFF|0|0
45.06|3560|Cam Ctrl. OFF|0|0
45.33|3680|Cam Ctrl. OFF|0|0
45.60|3680|Cam Ctrl. OFF|0|0
45.88|3720|Cam Ctrl. OFF|0|0
46.15|3800|Cam Ctrl. OFF|0|0
46.43|3920|Cam Ctrl. OFF|0|0
46.72|4040|Cam Ctrl. OFF|0|0
46.99|4160|Cam Ctrl. OFF|0|0
47.27|4280|Cam Ctrl. OFF|0|0
47.55|4400|Cam Ctrl. OFF|0|0
47.84|4520|Cam Ctrl. OFF|0|0
48.18|4680|Cam Ctrl. OFF|0|0
48.51|4800|Cam Ctrl. OFF|0|0
48.82|4760|Cam Ctrl. OFF|0|0
49.14|4720|Cam Ctrl. OFF|0|0
49.41|4680|Cam Ctrl. OFF|0|0
49.70|4640|Cam Ctrl. OFF|0|0
49.95|4600|Cam Ctrl. OFF|0|0
50.22|4520|Cam Ctrl. OFF|0|0
50.50|4480|Cam Ctrl. OFF|0|0
50.77|4400|Cam Ctrl. OFF|0|0
51.06|4360|Cam Ctrl. OFF|0|0
51.32|4280|Cam Ctrl. OFF|0|0
51.60|4200|Cam Ctrl. OFF|0|0
51.87|4160|Cam Ctrl. OFF|0|0
52.15|4080|Cam Ctrl. OFF|0|0
52.42|4040|Cam Ctrl. OFF|0|0
52.70|3960|Cam Ctrl. OFF|0|0
52.97|3880|Cam Ctrl. OFF|0|0
53.25|3800|Cam Ctrl. OFF|0|0
53.58|3720|Cam Ctrl. OFF|0|0
53.85|3640|Cam Ctrl. OFF|0|0
54.13|3600|Cam Ctrl. OFF|0|0
54.40|3520|Cam Ctrl. OFF|0|0
54.68|3440|Cam Ctrl. OFF|3|0
54.95|3400|Cam Ctrl. OFF|3|0
55.23|3320|Cam Ctrl. OFF|3|0
55.50|3240|Cam Ctrl. OFF|3|0
55.78|3240|Cam Ctrl. OFF|3|0
56.05|3240|Cam Ctrl. OFF|3|0
56.33|3160|Cam Ctrl. OFF|3|0
56.60|3160|Cam Ctrl. OFF|3|0
56.88|3120|Cam Ctrl. OFF|3|0
57.16|3120|Cam Ctrl. OFF|0|0
57.43|3080|Cam Ctrl. OFF|0|0
57.70|3080|Cam Ctrl. OFF|0|0
57.98|3040|Cam Ctrl. OFF|0|0
58.25|3040|Cam Ctrl. OFF|0|0
58.58|3000|Cam Ctrl. OFF|0|0
58.86|3000|Cam Ctrl. OFF|0|0
59.13|2960|Cam Ctrl. OFF|0|0
59.41|2960|Cam Ctrl. OFF|0|0
59.68|2920|Cam Ctrl. OFF|0|0
59.96|2920|Cam Ctrl. OFF|0|0
60.23|2920|Cam Ctrl. OFF|0|0
60.51|3000|Cam Ctrl. OFF|0|0
60.78|2960|Cam Ctrl. OFF|0|3
61.06|2960|Cam Ctrl. OFF|0|0
61.34|2960|Cam Ctrl. OFF|0|0
61.61|2960|Cam Ctrl. OFF|0|0
61.88|2960|Cam Ctrl. OFF|0|0
62.16|2960|Cam Ctrl. OFF|0|0
62.43|3000|Cam Ctrl. OFF|0|0
62.71|3000|Cam Ctrl. OFF|0|0
62.99|2960|Cam Ctrl. OFF|0|0
63.26|2800|Cam Ctrl. OFF|0|0
63.59|2720|Cam Ctrl. OFF|0|0
63.87|2680|Cam Ctrl. OFF|0|0
64.13|2600|Cam Ctrl. OFF|0|-1
64.41|2560|Cam Ctrl. OFF|0|2
64.69|2520|Cam Ctrl. OFF|0|-1
64.96|2480|Cam Ctrl. OFF|0|-1
65.23|2480|Cam Ctrl. OFF|0|-1
65.51|2440|Cam Ctrl. OFF|0|-1
65.79|2400|Cam Ctrl. OFF|0|-1
66.06|2360|Cam Ctrl. OFF|0|-1
66.34|2320|Cam Ctrl. OFF|0|-1
66.62|2480|Cam Ctrl. OFF|0|-1
66.89|2640|Cam Ctrl. OFF|0|-1
67.16|2720|Cam Ctrl. OFF|0|-1
67.44|2760|Cam Ctrl. OFF|0|-1
67.71|2800|Cam Ctrl. OFF|0|-1
67.99|2880|Cam Ctrl. OFF|0|-1
68.26|2920|Cam Ctrl. OFF|0|-1
68.54|3000|Cam Ctrl. OFF|0|-1
68.81|3040|Cam Ctrl. OFF|3|-1
69.09|3080|Cam Ctrl. OFF|3|-1
69.36|3160|Cam Ctrl. OFF|3|-1
69.63|3200|Cam Ctrl. OFF|3|-1
69.91|3000|Cam Ctrl. OFF|0|-1
70.19|2960|Cam Ctrl. OFF|0|-1
70.47|2960|Cam Ctrl. OFF|0|-1
70.74|2960|Cam Ctrl. OFF|0|-1
71.01|2920|Cam Ctrl. OFF|0|-1
71.28|2880|Cam Ctrl. OFF|0|-1
71.56|2880|Cam Ctrl. OFF|0|-1
71.83|2880|Cam Ctrl. OFF|0|-1
72.11|2880|Cam Ctrl. OFF|0|-1
72.38|2880|Cam Ctrl. OFF|0|-1
72.66|2880|Cam Ctrl. OFF|0|-1
72.94|2880|Cam Ctrl. OFF|0|-1
73.20|2880|Cam Ctrl. OFF|0|-1
73.48|2880|Cam Ctrl. OFF|0|-1
73.76|2840|Cam Ctrl. OFF|0|-1
74.04|2840|Cam Ctrl. OFF|0|-1
74.32|2840|Cam Ctrl. OFF|0|-1
74.59|2840|Cam Ctrl. OFF|0|-1
74.86|2840|Cam Ctrl. OFF|0|-1
75.13|2840|Cam Ctrl. OFF|0|-1
75.41|2800|Cam Ctrl. OFF|0|-1
75.68|2800|Cam Ctrl. OFF|0|-1
75.96|2760|Cam Ctrl. OFF|0|-1
76.23|2760|Cam Ctrl. OFF|0|-1
76.51|2720|Cam Ctrl. OFF|0|-1
76.78|2680|Cam Ctrl. OFF|0|2
77.06|2640|Cam Ctrl. OFF|0|-1
77.34|2600|Cam Ctrl. OFF|0|2
77.61|2720|Cam Ctrl. OFF|0|-1
77.89|2880|Cam Ctrl. OFF|0|2
78.15|2880|Cam Ctrl. OFF|0|2
78.43|2960|Cam Ctrl. OFF|0|-1
78.71|3040|Cam Ctrl. OFF|3|-1
78.99|3040|Cam Ctrl. OFF|3|-1
79.27|3080|Cam Ctrl. OFF|3|-1
79.53|3160|Cam Ctrl. OFF|3|-1
79.80|3160|Cam Ctrl. OFF|3|-1
80.09|3240|Cam Ctrl. OFF|3|-1
80.36|3280|Cam Ctrl. OFF|3|-1
80.63|3280|Cam Ctrl. OFF|3|-1
80.91|3360|Cam Ctrl. OFF|3|-1
81.19|3360|Cam Ctrl. OFF|3|-1
81.46|3400|Cam Ctrl. OFF|0|-1
81.74|3440|Cam Ctrl. OFF|0|-1
82.01|3480|Cam Ctrl. OFF|0|-1
82.28|3440|Cam Ctrl. OFF|0|-1
82.55|3360|Cam Ctrl. OFF|0|-1
82.84|3360|Cam Ctrl. OFF|0|-1
83.11|3400|Cam Ctrl. OFF|3|-1
83.39|3440|Cam Ctrl. OFF|0|-1
83.66|3440|Cam Ctrl. OFF|3|-1
83.94|3440|Cam Ctrl. OFF|3|-1
84.20|3400|Cam Ctrl. OFF|3|-1
84.48|3320|Cam Ctrl. OFF|3|-1
84.75|3160|Cam Ctrl. OFF|0|-1
85.03|3160|Cam Ctrl. OFF|0|-1
85.31|3040|Cam Ctrl. OFF|0|-1
85.58|2960|Cam Ctrl. OFF|0|-1
85.86|2880|Cam Ctrl. OFF|0|-1
86.13|2760|Cam Ctrl. OFF|0|-1
86.41|2600|Cam Ctrl. OFF|0|-1
86.68|2720|Cam Ctrl. OFF|0|2
86.96|2800|Cam Ctrl. OFF|0|-1
87.23|2760|Cam Ctrl. OFF|0|-1
87.52|2760|Cam Ctrl. OFF|0|2
87.78|2760|Cam Ctrl. OFF|0|-1
88.05|2760|Cam Ctrl. OFF|0|-1
88.33|2560|Cam Ctrl. OFF|0|2
88.61|2400|Cam Ctrl. OFF|0|-1
88.88|2320|Cam Ctrl. OFF|0|-1
89.16|2240|Cam Ctrl. OFF|0|-1
89.43|2160|Cam Ctrl. OFF|0|-1
89.71|2080|Cam Ctrl. OFF|0|-1
89.98|2000|Cam Ctrl. OFF|0|2
90.25|1920|Cam Ctrl. OFF|0|-1
90.53|1840|Cam Ctrl. OFF|0|-1
90.80|1760|Cam Ctrl. OFF|0|-1
91.08|1680|Cam Ctrl. OFF|0|-1
91.36|1600|Cam Ctrl. OFF|0|-1
91.63|1560|Cam Ctrl. OFF|0|-1
91.91|1480|Cam Ctrl. OFF|0|2
92.18|1400|Cam Ctrl. OFF|0|-1
92.46|1320|Cam Ctrl. OFF|0|-1
92.73|1280|Cam Ctrl. OFF|0|-1
93.00|1480|Cam Ctrl. OFF|0|-1
93.28|1720|Cam Ctrl. OFF|0|-1
93.56|1800|Cam Ctrl. OFF|0|-1
93.83|1920|Cam Ctrl. OFF|0|-1
94.11|2000|Cam Ctrl. OFF|0|-1
94.38|2040|Cam Ctrl. OFF|0|-1
94.65|2080|Cam Ctrl. OFF|0|-1
94.93|2160|Cam Ctrl. OFF|0|2
95.21|2200|Cam Ctrl. OFF|0|2
95.48|2240|Cam Ctrl. OFF|0|2
95.76|2280|Cam Ctrl. OFF|0|2
96.03|2320|Cam Ctrl. OFF|0|-1
96.31|2360|Cam Ctrl. OFF|0|-1
96.58|2360|Cam Ctrl. OFF|0|2
96.86|2400|Cam Ctrl. OFF|0|2
97.13|2440|Cam Ctrl. OFF|0|2
97.40|2480|Cam Ctrl. OFF|0|2
97.68|2520|Cam Ctrl. OFF|0|2
97.96|2560|Cam Ctrl. OFF|0|-1
98.23|2600|Cam Ctrl. OFF|0|-1
98.51|2640|Cam Ctrl. OFF|0|-1
98.78|2680|Cam Ctrl. OFF|0|2
99.05|2720|Cam Ctrl. OFF|0|-1
99.33|2760|Cam Ctrl. OFF|0|2
99.61|2760|Cam Ctrl. OFF|0|-1
99.88|2800|Cam Ctrl. OFF|0|-1
100.16|2840|Cam Ctrl. OFF|0|2
100.43|2880|Cam Ctrl. OFF|0|2
100.70|2920|Cam Ctrl. OFF|0|-1
100.98|2960|Cam Ctrl. OFF|3|2
101.25|2960|Cam Ctrl. OFF|3|-1
101.53|3000|Cam Ctrl. OFF|3|-1
101.80|3040|Cam Ctrl. OFF|3|2
102.08|3080|Cam Ctrl. OFF|3|2
102.35|3040|Cam Ctrl. OFF|3|2
102.63|3080|Cam Ctrl. OFF|3|-1
102.91|3080|Cam Ctrl. OFF|3|-1
103.18|3040|Cam Ctrl. OFF|0|-1
103.45|3040|Cam Ctrl. OFF|3|-1
103.73|3000|Cam Ctrl. OFF|0|2
104.00|2960|Cam Ctrl. OFF|0|2
104.28|2920|Cam Ctrl. OFF|0|-1
104.56|2920|Cam Ctrl. OFF|0|-1
104.83|2880|Cam Ctrl. OFF|0|-1
105.10|2880|Cam Ctrl. OFF|0|2
105.38|2840|Cam Ctrl. OFF|0|-1
105.66|2840|Cam Ctrl. OFF|0|-1
105.93|2840|Cam Ctrl. OFF|0|-1
106.21|2800|Cam Ctrl. OFF|0|-1
106.48|2800|Cam Ctrl. OFF|0|2
106.75|2800|Cam Ctrl. OFF|0|-1
107.03|2800|Cam Ctrl. OFF|0|-1
107.30|2800|Cam Ctrl. OFF|0|2
107.58|2800|Cam Ctrl. OFF|0|2
107.86|2760|Cam Ctrl. OFF|0|-1
108.13|2760|Cam Ctrl. OFF|0|-1
108.40|2760|Cam Ctrl. OFF|0|-1
108.68|2760|Cam Ctrl. OFF|0|-1
108.96|2720|Cam Ctrl. OFF|0|-1
109.23|2520|Cam Ctrl. OFF|0|2
109.51|2440|Cam Ctrl. OFF|0|-1
109.78|2400|Cam Ctrl. OFF|0|-1
110.06|2320|Cam Ctrl. OFF|0|-1
110.38|2280|Cam Ctrl. OFF|0|-1
110.66|2240|Cam Ctrl. OFF|0|-1
110.94|2160|Cam Ctrl. OFF|0|-1
111.21|2160|Cam Ctrl. OFF|0|-1
111.49|2120|Cam Ctrl. OFF|0|-1
111.76|2040|Cam Ctrl. OFF|0|-1
112.04|2000|Cam Ctrl. OFF|0|-1
112.31|1960|Cam Ctrl. OFF|0|-1
112.58|1920|Cam Ctrl. OFF|0|-1
112.86|1920|Cam Ctrl. OFF|0|-1
113.14|1840|Cam Ctrl. OFF|0|-1
113.41|1800|Cam Ctrl. OFF|0|-1
113.69|1800|Cam Ctrl. OFF|0|-1
113.96|1720|Cam Ctrl. OFF|0|-1
114.24|1680|Cam Ctrl. OFF|0|-1
114.51|1640|Cam Ctrl. OFF|0|-1
114.79|1600|Cam Ctrl. OFF|0|-1
115.06|1560|Cam Ctrl. OFF|0|-1
115.34|1440|Cam Ctrl. OFF|0|-1
115.61|1360|Cam Ctrl. OFF|0|-1
115.89|1240|Cam Ctrl. OFF|0|-1
116.16|1200|Cam Ctrl. OFF|0|-1
116.44|1080|Cam Ctrl. OFF|0|-1
116.70|1040|Cam Ctrl. OFF|0|-1
116.99|1000|Cam Ctrl. OFF|0|-1
117.26|1000|Cam Ctrl. OFF|0|-1
117.54| 960|Cam Ctrl. OFF|0|-1
117.81| 960|Cam Ctrl. OFF|0|-1
118.09| 920|Cam Ctrl. OFF|0|0
118.36| 960|Cam Ctrl. OFF|0|0
118.63| 920|Cam Ctrl. OFF|0|0
118.91| 920|Cam Ctrl. OFF|0|0
119.19| 920|Cam Ctrl. OFF|0|0
119.46| 880|Cam Ctrl. OFF|0|3
119.74|1200|Cam Ctrl. OFF|0|0
120.01|1600|Cam Ctrl. OFF|0|0
120.29|1680|Cam Ctrl. OFF|0|0
120.56|1720|Cam Ctrl. OFF|0|0
120.84|1760|Cam Ctrl. OFF|0|0
121.11|1760|Cam Ctrl. OFF|0|0
121.39|1800|Cam Ctrl. OFF|0|0
121.66|1800|Cam Ctrl. OFF|0|0
121.93|1840|Cam Ctrl. OFF|0|0
122.21|1880|Cam Ctrl. OFF|0|0
122.49|1880|Cam Ctrl. OFF|0|0
122.76|1880|Cam Ctrl. OFF|0|0
123.04|1600|Cam Ctrl. OFF|0|0
123.30|1440|Cam Ctrl. OFF|0|0
123.59|1320|Cam Ctrl. OFF|0|0
123.85|1280|Cam Ctrl. OFF|0|0
124.14|1200|Cam Ctrl. OFF|0|-1
124.40|1160|Cam Ctrl. OFF|0|2
124.69|1080|Cam Ctrl. OFF|0|-1
124.96|1200|Cam Ctrl. OFF|0|2
125.24|1400|Cam Ctrl. OFF|0|-1
125.50|1600|Cam Ctrl. OFF|0|-1
125.79|1600|Cam Ctrl. OFF|0|-1
126.06|1280|Cam Ctrl. OFF|0|2
126.33|1240|Cam Ctrl. OFF|0|-1
126.61|1160|Cam Ctrl. OFF|0|2
126.88|1080|Cam Ctrl. OFF|0|-1
127.15|1040|Cam Ctrl. OFF|0|-1
127.43|1000|Cam Ctrl. OFF|0|-1
127.77| 960|Cam Ctrl. OFF|0|-1
128.03| 920|Cam Ctrl. OFF|0|-1
128.31| 880|Cam Ctrl. OFF|0|-1
128.59| 840|Cam Ctrl. OFF|0|-1
128.87| 840|Cam Ctrl. OFF|0|2
129.13| 800|Cam Ctrl. OFF|0|2
129.42| 840|Cam Ctrl. OFF|0|-1
129.68| 800|Cam Ctrl. OFF|0|2
129.96| 800|Cam Ctrl. OFF|0|-1
130.23| 760|Cam Ctrl. OFF|0|-1
130.52| 760|Cam Ctrl. OFF|0|-1
130.78| 760|Cam Ctrl. OFF|0|-1
131.06| 680|Cam Ctrl. OFF|0|-1
131.33| 640|Cam Ctrl. OFF|0|2
131.61| 640|Cam Ctrl. OFF|0|-1
131.88| 680|Cam Ctrl. OFF|0|-1
132.16| 680|Cam Ctrl. OFF|0|2
132.43| 680|Cam Ctrl. OFF|0|2
132.71| 640|Cam Ctrl. OFF|0|-1
132.98| 640|Cam Ctrl. OFF|0|-1
133.26| 640|Cam Ctrl. OFF|0|-1
133.54| 640|Cam Ctrl. OFF|0|2
133.81| 680|Cam Ctrl. OFF|0|2
134.08| 680|Cam Ctrl. OFF|0|-1
134.36| 640|Cam Ctrl. OFF|0|-1
134.63| 600|Cam Ctrl. OFF|0|2
134.91| 640|Cam Ctrl. OFF|0|2
135.18| 680|Cam Ctrl. OFF|0|-1
135.46| 680|Cam Ctrl. OFF|0|-1
135.73| 680|Cam Ctrl. OFF|0|-1
136.01| 680|Cam Ctrl. OFF|0|-1
136.28| 680|Cam Ctrl. OFF|0|2
136.56| 680|Cam Ctrl. OFF|0|-1
136.83| 680|Cam Ctrl. OFF|0|-1
137.11| 680|Cam Ctrl. OFF|0|-1
137.38| 720|Cam Ctrl. OFF|0|2
137.66| 680|Cam Ctrl. OFF|0|2
137.93| 680|Cam Ctrl. OFF|0|2
138.21| 680|Cam Ctrl. OFF|0|-1
138.48| 680|Cam Ctrl. OFF|0|-1
138.76| 680|Cam Ctrl. OFF|0|2
139.03| 680|Cam Ctrl. OFF|0|-1
139.31| 640|Cam Ctrl. OFF|0|-1
139.58| 640|Cam Ctrl. OFF|0|-1
139.86| 640|Cam Ctrl. OFF|0|-1
140.13| 640|Cam Ctrl. OFF|0|2
140.41| 640|Cam Ctrl. OFF|0|-1
140.68| 640|Cam Ctrl. OFF|0|2
140.96| 640|Cam Ctrl. OFF|0|-1
141.23| 680|Cam Ctrl. OFF|0|2
141.51| 680|Cam Ctrl. OFF|0|2
141.78| 640|Cam Ctrl. OFF|0|-1
142.06| 640|Cam Ctrl. OFF|0|-1
142.33| 680|Cam Ctrl. OFF|0|2
142.61| 680|Cam Ctrl. OFF|0|-1
142.89| 680|Cam Ctrl. OFF|0|-1
143.16| 680|Cam Ctrl. OFF|0|-1
143.43| 720|Cam Ctrl. OFF|0|-1
143.71| 760|Cam Ctrl. OFF|0|-1
143.98| 760|Cam Ctrl. OFF|0|-1
144.26| 720|Cam Ctrl. OFF|0|2
144.53| 680|Cam Ctrl. OFF|0|-1
144.81| 680|Cam Ctrl. OFF|0|-1
145.08| 720|Cam Ctrl. OFF|0|2
145.36| 720|Cam Ctrl. OFF|0|2
145.63| 680|Cam Ctrl. OFF|0|-1
145.91| 680|Cam Ctrl. OFF|0|2
146.18| 640|Cam Ctrl. OFF|0|2

[cparke]

Also BTW --- this fault code has come up about 3-4 times in the past few months.

17746 - Camshaft Position Sensor (G40): Open or Short to Plus
P1338 - 35-10 - - - Intermittent

This is the Bank 2 sensor. I took it off and the wiring and component looked just fine to me. Haven't seen the code get thrown in some time now, but since we are talking about camshaft adjustment not happening when it should, thought it would be best to throw this out there too.

Appreciate any further thoughts you might have.

[Affinitive]

Hi Colin,


Haven't looked at the oil pressure switch at all. Are you talking about removing it, or just on the outside?

No just look at it to tell what color it is. The were a total of 5 different pressure switches for these old ones. The black and white are always used for engine oil pressure warning indicators/buzzers...... Some of the old VW stuff would also use a blue, a grey and very rarely a brown. All three of which had really low pressure working ranges. Basicly like load cut-off switches and that type of stuff so that heavy loads would not engage until it had at least a few PSI of pressure. Like I said, way out there in left field. Are you the original owner of the car??? If need be, you could see it with a telescoping mirror from the top. Given how weird things are, can't hurt to look.

Just worried that you bought the car when someone was trying to hide low oil pressure problems by using a lower rated pressure switch. Left field thing again

The valve timing stuff going on there is defintely wonky. Have you ever had any issue with lifter constantly bleeding off when the car sits for a while??? As in like the oil check valves underneath the intake being loose.

I would at this point check to see wether the cam adjusters are getting power applied when they are supposed to. Simple test light and jumper wires would do the trick and a little creativity laying the test light up on the wiper while driving. If that's good, then it's time to pull the valve covers upper timing belt covers to varify all base timing marks. At that point disable the ignition by unplugging the coil pack and while cranking the engine extended period of time with a remote starter switch hooked up, manually apply power to the cam adjusters while cranking, If oil pressure is sufficient, it'll be enough to move the adjusters to the advanced position even while cranking, though they'll move kinda slow since oil pressure will be fairly low while cranking. Provided of course it has the correct oil pressure switch installed. If not, then you know someone is obviously trying to hide a low pressure problem. Low pressure will also affect the engine's ability to pump air.

To kinda back up on the manifold vacuum thing. Definitely wana know what a gauge shows and wether it's steady vacuum. Quickest and easiest thing to check first.

As for the adaptation value being kicked up one notch, someone may have set the idle rpm 10 rpm's higher just to help smooth idle vibration. Idle vibrations get more noticeable over time as rubber motor mounts become hardened from all the heat. Though just for sh!ts and grins, go ahead and set the adaptation value to 124 (the lowest possible setting) and let it idle for a while so the oil gets nice and hot and thins out as much as possible. Or even drive it a while then let it idle. Even a the lowest possible idle speed, it should still be able to easily maintain good pressure. Who knows, maybe someone set the idle up just a touch to hide a pressure problem. I'm assuming it has the correct oil filter on it, and a good quality filter at that, right???

Sorry, this post was kinda all over the board there.

Let me know, we'll figure it out, it's just a car.

C

[cparke]

Hi Colin,

Okay, I can say a few things for certainty here, as well as simplify some of your test instructions considerably.

For sure, I am not the original owner of the car and I did acquire it with this problem. The previous owner deferred a lot of maintenance and tended to do essential repairs as cheaply as possible and clearly allowed some problems to develop on top of each other. The timing belt was changed before I got the car, it looks nice and new when uncovered, I think we have a consensus that checking valve timing is definitely an appropriate step at this point.

Regard the adaptation channel 1 value, the ECU currently installed is a second ECU I got to replace my original one with the GIAC chip installed and to verify the ECU itself is not my problem. My old ECU had 129 in adaptation channel #1. When I installed the new ECU, it was coded for front-wheel drive only and had an adaptation value of 128. However, immediately after I re-coded it for all wheel drive (before even starting the engine), the adaptation value went to 129. So, 129 is the factory default for adaptation channel 1 when ECU is coded for Quattro, and that is what my the stock ECU is currently set at. Nobody fooled with idle speed.

The cam adjusters are getting power applied when they are supposed to. Output Diagnostic Test Mode (DTM) has a step where the ECU actuates the cam adjusters without the engine running. Both of my cam adjusters audibly click, and I can feel it happening with my finger too. An LED can be connected to the wiring harness while DTM is running if this didn't happen, so there is no need to go driving around with a LED connected to just test the wiring under any circumstances. To disable the ignition, I believe you also should pull the fuel pump fuse, as that is supposed to disable the fuel injectors too.

The oil filter is a Mighty Auto Parts "Engine Guard II" oil filter M2901, which was installed by a service station at my last oil change. All I can see of the oil pressure switch is the white rubber cover over the wiring connection---not sure if that is part of the switch or not (rubber doesn't slide off very easily and I'm not going to force it and break something!) The car does leak oil (oil is on the wiring to the oil pressure switch too), I have been assuming it is from the valve covers, but it is absolutely possible it is also leaking from somewhere else like these oil check valves too. Personally, I've wanted to think the oil leak is the cause of running rich, but no one has ever be confident enough with me that an oil leak alone could cause this to happen.

The car should get the vacuum, timing, fuel pressure, oil pressure checks and whatever else is appropriate done today, and hopefully we will know tonight what the problem actually is, and maybe it will even be fixed! (hooray!) If not, I am going to be very, very disappointed.

Thanks so much for all your help. Amazing how many things could go wrong to cause a problem like this to crop up.

[Affinitive]

HUH -

Interesting, I've never seen 129 being set as factory default idle adaptation value. Always has been 128 and all service manuals I ever read through always specified 128 to be set when needed. When replacing modules, service manuals always specify to set proper coding and adaptation values as there is guarantee everything to preset correctly. May have something to do with control modules also used in markets outside of US. Kinda like ordering an ABS module by VIN number yet the coding numbers still need to be adjusted. Whatever, kinda irrelevant. Was just trying to explore or entertain wild ideas. Though I myself would still temporarily set the idle adaptation to the lowest possible setting of 124 just to get a better idea of wether the engine is able to maintain proper oil pressure while idling as it should. Whatever, I guess it's that left field thing again. Just thought it would be a halfway decent clue to wether pressure is too low to operate the cam adjusters.

As for the oil pressure switch thing, even with the white rubber sleeve over the wire connector, you'll still be able to see the color of the plastic between the meatl part of the switch and rubber sleeve. The oil pressure switches are also common to leaking just as a side note.

As for the output test. That's all it is, a component output test. Running the out put test varifies the wiring to be intact and wether the specific component seems to be working. It has not to do with wether the ECM is properly activating the component during normal vehicle operation. Though I do have to say that I have never seen a car where live data showed no Cam adjustment "request/comand" when it it's suppossed to. I'm also curious to see the condition of the cam adjusters with the valve covers removed. Unfortunately these things can break the plastic chain guides on the adjusters and many times make no unusual noise. This could explain the fluctuations in the cam timing. I also mentioned the check valves because they could bleed off oil pressure before the cylinder heads in turn starving the heads for oil pressure which could be one reason why the cam adjusters are not moving. I forgot to mention these check valves being covered by the valley plate/ block breather plate which is under the intake manifold. So they are not gonna cause an external oil leak. The question of wether the lifters frequently bleed off oil would be an indication of the check valves having come loose and allowing the oil in the heads to drain back into the pan evertime the engine is shut off. Maybe the left field thing again. Though I'm still perplexed about the lack of cam adjustment request/comand (the ON/OFF part of 090 measuring block). Does it do the same thing with the other ECM. Something else to consider regarding one of these older ECM's. Cam adjustment faults will only set when adjustment range exceeds 25 degrees, like the base timing not being set correctly or a spun chain sprocket (which is extremely rare). The cam position sensor faults will/can set when when the cam adjustemtn range is not reached within a certain period of time. Basicly you would have to hold the rpm's high for extended period of time.

I'm not sure what you mean about an oil leak causing fuel trim issues. You mean like the engine consuming so much smokes to fool the O2 sensors. it would have to smoking so bad that the car would not be driveable and you'd be pouring oil in every 20 minutes. I guarantee you that you can dismiss that idea.

Again, I appologise about the last post being all over the board. Was in a hurry and hope this clarifies things. Over the years, I've had to come up with many unusual "detective" strategies to track down odd and unusual problems. far too often finding multiple issue compiling to what seems like one blatant concern. Just trying to think outside the box. Sorry if I'm making things more confussing.

Anywho, obviously we both agree on the need to isolate valve timing concerns and manifold vacuum.

C

[cparke]

Hi Colin,

First of all, my apologies, the stored value in adaptation channel is 128 and always has been. That's what my saved logs tell me. I don't know where I got the idea that 129 was the setting for Quattro. Weird of me.

Okay, I had the car looked at today by an Audi specialist repair. No, he didn't check the vacuum pressure or the valve timing. Instead, he insisted on trying a known good MAF on the car even though I had already changed it for a new one (that was the first part I changed on the engine!) and dismissed the MAF as not the cause. What is particularly eye-opening about this is that the fuel trim learn values developed dramatically different:

10:18:38 Group 032: O2S control learning values (before Cat. Conv.) [B=Bank S=Sensor]
-3.9 % @idle B1S1 +/-10%
-2.3 % @part B1S1 +/-10%
-4.7 % @idle B2S1 +/-10%
1.6 % @part B2S1 +/-10%

Never have I seen a positive value in the trim learn values before, at any point. My mistake was trusting that a new MAF will be a good MAF, apparently that isn't necessarily so! So, in other words, we're saying the new MAF that I got was nevertheless bad, and everything else I've been trying to do over the past 2 months may have been pointless.

The MAF I bought 2 months ago is under a 1-year warranty, and the repair shop didn't have a new MAF in stock, so it was a given that I should return/exchange the new MAF first before he goes and orders one for me.

For more great laughs (maybe you have some deeper insight too), I decided to re-install my original MAF which has been sitting in a box for the past 2 months since I got the new one, to get some learn values for my drive home. After clearing the learn values and then driving home (a much longer run that my test drive with the known-good MAF), here's what my learn values developed into:

11:53:53 Group 032: O2S control learning values (before Cat. Conv.) [B=Bank S=Sensor]
-6.3 % @idle B1S1 +/-10%
-4.7 % @part B1S1 +/-10%
-7.8 % @idle B2S1 +/-10%
3.1 % @part B2S1 +/-10%

Unfortunately, this was a short-lived phenomenon. Clearing the learn values again and doing a test drive, B2S1 multiplicative initially learns to -0.8 and then slowly moves in the negative direction, and B1S1 multiplicative still reaches -10.8 after more extensive driving. However, this is much better than how the "new" MAF was behaving most recently, when the B1S1 multiplicative learn values quickly jumped in the -10 or more during an initial test drive.

I guess the original MAF is also bad, it just behaved properly for a short period time after being dormant for 2 months. Is that normal? Is it heat that slowly causes the MAF to slowly distort its readings and report more and more false air and eventually lose all calibration, all the time? That seems to be how my original MAF has been behaving today when it got powered up again after a very long sleep.

Knowing what learn values should develop in the car with a good MAF is key to getting a good replacement. How frustrating it is that new parts nevertheless can be bad from day 1 or go bad quickly once installed. Let's leave the measuring block 90 anomalies aside for the time being---the car's fuel trim is messed up from a bad MAF and could be running lean or rich at any given moment. Also, the ECU might simply be disabling camshaft adjustment when certain fault codes like TOO RICH or LOAD CALCULATION CROSS-CHECK have been thrown. After I finally get a good MAF (what I wanted from the beginning) and the car maintains appropriate fuel trim numbers, then we can see if those problems are still there or not and if they are important to address or not.

[Affinitive]

Well, unfortunately it does happen sometimes to recieve defective parts. Luckily it's pretty rare though.
In your case though, it still doesn't quite jive though. First of all, these Hitachi Air Mass Meters don't go bad all too often. Then to recieve a defective unit would be odd also, especially if it was a new unit. Many "rebuilt" Air Mass Meters don't work right out of the box........

What's even more odd would be that your air mass meter would have been giving unusually high Grams per second (g/s) air flow readings to be causing you're specific problem. Then to recieve another air mass meter giving falsely high g/s readings would be extremely unusual. Usually air mass meter fail giving low g/s readings. But again though, the Hitachi Air Mass Meters don't fail very often, very seldomly.

What g/s air flow rate was the tech seeing to say he wanted to try a know good part. Both idle and full load peak rpm. You should be getting about 3 - 4 g/s at idle at operating temp. Slightly below 3 is fine. At full throttle and just under redline it should be pulling about 135 - 155 g/s. So again, BOTH air mass meters were giving falsely high g/s readings???
No offense, but I have a very hard time believing it. Just to put it into perspective, to this day I have only seen one air meter give high readings causing rich trim faults. But not really though, that particualr car belonged to an old lady. Once giving it a good drive, it turned out to be giving a low reading in the higher rpm range and the low rpm range started going back to somewhat normal and ultimately started giving lean trim faults like typical.

I know this whole situation is just all too weird to begin with, but this is sounding like an idea beyond left field.

Sorry again about the delay here.

Can you log the g/s of the air mass meter readings along rpm

Thanx

C

[cparke]

Hi Colin,

These past few days I've running the car with my original MAF (yeah, it is the 10 years old one) with the airbox disconnected like the tech. did, and I am getting the same kind of good trim values. The MAF I got from the parts dealer was ordered to be new but I actually received a "rebuilt" one. I didn't like that when I got it, but heh isn't it just as good? (apparently, no).

The previous owner admitted to me this week that the car had been running "cool", which suggests that the ECT may have been part of the problem all along, but because the MAF was the first thing I changed, and I left it installed, I didn't know I had fixed the problem when I did. My bet is the ECT, intake duct gasket, jet suction pump (purge valve), and the EVAP purge valve all must have contributed to fixing the problem (hence the ECU's fit of rage after each install). Not sure about the fuel pressure regulator, probably should keep the new one installed anyway?

Anyway, the dealer is replacing the "rebuilt" MAF with a real new one today under warranty. Since the original MAF seems to be working fine now, I'm not expecting much of a difference from an actual new MAF, but I will need to test it out, and it might be interesting to see if trims remain like they are now. Definitely though, it looks like my fuel trim problems are over since going back to square one with the MAF. Haven't looked at cam adjustment or knock sensors recently, but I will soon.

Thanks for your thoughts and help.

[Affinitive]

Well I'm glad that things seem to be looking better finally. I was starting to think that all this was just way too weird.

Though, what do you mean with "Airbox Disconnected"???

C