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EuroDriven
11-24-2010, 03:36 PM
I am having some issues with my BT build that I cannot figure out.

To start out with I refuse to believe it is as simple as a vacuum leak, boost leak or TBA. This is because I have done a TBA, and cannot find any vacuum leaks. I have not done a boost leak check but I cannot believe it would cause an issue like this.

Car = 1998 b5 a4 1.8 tqm w/ 3071r

The problem I am having is the idle will not not return to idle after revving it, tonight I have been having issues trying to get it have a stable idle. When the car is idling I will rev the engine, it will run fine at 2000 rpms, 3000 rpms, 2500 rpms, whatever. Then when I let go of the throttle the engine will go back down to idle, but over shoot and then try to rev itself back up to get to the correct idle rpms.

I have been searching and searching for weeks and haven't been able to find anything until now. I found the following thread and feel like this is the issue.

http://www.audi-forums.com/b5-forum/43505-erratic-idle-2.html

Thread cliff notes ^:
-issue is combination of dirty maf, icv and dirty butterfly valve
-carbon deposits can build up on the edges of the butterfly valve in the throttle body and affect readings. (aka read like it should at 2% when the valve is really at 3%)
-clean/replace throttle body to fix

1. Is there anybody else who has seen, or dealt with this issue?
2. Are there any other causes of this?
3. Could a vacuum leak cause this? (I doubt it)
4. Could a small boost leak cause this? (note: the leak would have to be very small)
5. Is there a ICV "idle control valve" on a DBC AEB?

Any/all help is appreciated!

Thanks.

EuroDriven
11-24-2010, 05:14 PM
I cleaned the TB with no luck. I was told the person who told me that boost leaks wouldn't effect this is wrong so I went through and tightened up all the IC Piping to be sure about that since I don't have an air compressor.

Something I learn from vag-com is that the timing is all over the place, from 19* BTDC down to 3* BTDC. Is this normal? or is this another symptom of my issue?

flynnr
11-25-2010, 09:16 PM
i would 1st rule out any leaks... make yourself a boost leak tester for $20 and go to a gas station and use their free air compressor there. i made my own and it worked excellent.

other than that i dont have any recommendations. is your AC on? my idle is messed when my ac is running.

Poopie
11-26-2010, 06:15 AM
i'm thinking ecu

ricekikr
11-26-2010, 06:43 AM
Do you have a UEGO or any logs to give a better picture of whats going on?

My guesses:

1. Purge valve leaking (the solenoid on top of the airbox) - This will result in a rich to extremely rich condition, specially at idle. May not cause a CEL/Code - Try removing the hose and block any vacuum lines connected to it. - This has happened to me in twice, one in a BMW - caused rough idle and sometimes the engine won't shut down even with the key off. 2nd time in my AEB 1.8t, caused an extremely rich condition that engine couldn't idle, UEGO couldn't even display the AFR it was too rich. On both occasions I didn't get a CEL or even a code. Similar solution different symptoms.

2. Dirty Maf - Too little fuel

3. Fouled plugs - Too little spark

4. Throttle body - dirty - This caused my engine to suddenly shut down when depressing the clutch. Yours might be a little bit cleaner

5. Idle control busted - Erratic idle

6. Vacuum leak - Which is also a boost leak when under boost. - Will cause rough idle, but will also cause the engine to Idle higher not lower. How exactly did you check for a vacuum leak? Kinda hard to do, Boost leak is way easier.

7. Clogged injectors?


HTH

EuroDriven
11-26-2010, 10:38 AM
i would 1st rule out any leaks... make yourself a boost leak tester for $20 and go to a gas station and use their free air compressor there.

I can't since I can't drive it. Can I use the same type of compressor if I have one at home. Like the electric kind for bike tires, etc.



Do you have a UEGO or any logs to give a better picture of whats going on?

My guesses:

1. Purge valve leaking (the solenoid on top of the airbox) - This will result in a rich to extremely rich condition, specially at idle. May not cause a CEL/Code - Try removing the hose and block any vacuum lines connected to it. - This has happened to me in twice, one in a BMW - caused rough idle and sometimes the engine won't shut down even with the key off. 2nd time in my AEB 1.8t, caused an extremely rich condition that engine couldn't idle, UEGO couldn't even display the AFR it was too rich. On both occasions I didn't get a CEL or even a code. Similar solution different symptoms.

2. Dirty Maf - Too little fuel

3. Fouled plugs - Too little spark

4. Throttle body - dirty - This caused my engine to suddenly shut down when depressing the clutch. Yours might be a little bit cleaner

5. Idle control busted - Erratic idle

6. Vacuum leak - Which is also a boost leak when under boost. - Will cause rough idle, but will also cause the engine to Idle higher not lower. How exactly did you check for a vacuum leak? Kinda hard to do, Boost leak is way easier.

7. Clogged injectors?


HTH

1. I have the solenoid connected electronically but doesn't do anything, there is essentially nothing left of the stock vacuum system.
2. It is a brand new MAF, not sure how to check for too little fuel
3. It is misfiring and I keep cleaning the plugs, however I think it is fouling the plug because of the bigger issue, which is causing fouled plugs, if I can solve the bigger issue I can clean the plugs and they should be fine. (does this sound right?)
4. I just cleaned the throttle body so, the butterfly and tunnel is squeaky clean
5. How do I check the idle control valve and where is it?
6. I am connecting my boost gauge today to see if there is actually a vacuum being pulled at idle
7. This came up during a discussion with somebody, I bought them used, but am not sure where to get them flow matched or how much it would be.


It came up in my build thread that the software is written to have the DV recirculated, so I am going to try that today.

ricekikr
11-26-2010, 11:52 AM
2. Wideband gauge or check trims using any generic OBD reader / vagcom (isn't accurate but can give you rough estimate) LTFT and STFT = positive = lean / negative = rich

5. Its the same as the throttle. I meant the motor that controls the Idle inside the throttle (which opens the throttle to control Idle)

6. If you have a vacuum leak past the throttle body you will have high idle - easily seen thru vacuum/boost gauge. But if your vacuum leak is between the throttle and the MAF, it won't show in the vacuum gauge but can be seen in your trims, ECU will try to add fuel for the lean condition.

7. Try your old injectors / tune

DV - Hows it currently connected? If its a regular DV and its dumped to the atmosphere, it will definitely cause a rough idle because of MAF readings being wrong which can also cause a lean condition and the ECU will try to richen it back to stoich.

EuroDriven
11-26-2010, 12:13 PM
2. Wideband gauge or check trims using any generic OBD reader / vagcom (isn't accurate but can give you rough estimate) LTFT and STFT = positive = lean / negative = rich

5. Its the same as the throttle. I meant the motor that controls the Idle inside the throttle (which opens the throttle to control Idle)

6. If you have a vacuum leak past the throttle body you will have high idle - easily seen thru vacuum/boost gauge. But if your vacuum leak is between the throttle and the MAF, it won't show in the vacuum gauge but can be seen in your trims, ECU will try to add fuel for the lean condition.

7. Try your old injectors / tune

DV - Hows it currently connected? If its a regular DV and its dumped to the atmosphere, it will definitely cause a rough idle because of MAF readings being wrong which can also cause a lean condition and the ECU will try to richen it back to stoich.

2. How do I do this via vagcom? Should I log it then post here? What blocks to log?
5. I see the motor int here reacting to stop the motor from stalling but I have no idea how to tell if its working "right", it worked fine before the build.
7. Can't because there is no way (as far as I know) to un-flash an ECU, also I would need to build an entirely new intake

For the DV it is a turbo smart DV one port connected right before the throttle body, and the other 2 ports vented to atmosphere, the nipple is connected to the intake manifold.

naudi1.8
11-26-2010, 01:10 PM
How many miles since doing the tba? Last time I disconnected my intak throttle body coil packs and vacuum stuff I did a tba when I restared. My idle was doing just as you describe for about 10 miles and a few restarts then it smoothed out. Ran like $hit for those 10 miles, idle all over the place limp mode then it just cleared.

EuroDriven
11-26-2010, 01:14 PM
0 miles, I have not driven the car on the new setup yet. I have done a few TBA since the issue has started.

naudi1.8
11-26-2010, 05:38 PM
I would say go drive it. It takes some miles for the ecu to adapt after a tba. Any codes?

Poopie
11-26-2010, 08:37 PM
What tune? Your DV will be open to atmosphere causing incorrect maf readings at idle. Plug that DV vent port at idle to see if that immediately smooths it out after you reset the ecu.

winston@podi.ca
11-26-2010, 08:44 PM
Check the crankwheel trigger sensor.

Short version: I had my idle hunt like how you described in the OP, replaced the sensor and the problem went away.

Long version: **I'll edit this when I get really bored**

walky_talky20
11-26-2010, 09:39 PM
I'm with poopie on this. BOV + MAF = crappy idle. It has to be closed at idle or recirculated, else you'll have mixture problems.

EuroDriven
11-29-2010, 09:22 PM
update: got boost gauge installed and I am pulling 20 in-hg of a vacuum at idle, so I must not have a vacuum leak.

Since I don't have anything currently to connect the DV to the intake does it do about the same thing if I just block the blow off with my hand since air isn't escaping

I got all these codes below, I did some research on the TB codes and decided I would try a different TB.


VCDS-Lite Version: Release 1.1
Monday, 29 November 2010, 19:49:45:18855
Control Module Part Number: 8D0 907 557 R
Component and/or Version: 1.8L R4/5VT MOTR HS D05
Software Coding: 06201
Work Shop Code: WSC 06335
VCID: 3FF189582E73
5 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16687 - Cylinder 3: Misfire Detected
P0303 - 35-10 - - - Intermittent
16685 - Cylinder 1: Misfire Detected
P0301 - 35-10 - - - Intermittent
17953 - Throttle Valve Controller: Malfunction
P1545 - 35-10 - - - Intermittent
17967 - Throttle Body (J338): Fault in basic settings
P1559 - 35-10 - - - Intermittent


I have been getting some codes for the throttle body and couldn't figure out what to do so I went and grabbed the throttle body off the parts car of mine. I put the other TB on and it seems to idle MUCH better, the idle is very steady at 900 RPMs and the ignition timing I am pretty sure stayed solid at 12* BTDC. But the issue with this TB is that I was getting a P1559 code and it wouldn't clear so I couldn't do a TBA. I switched back to the TB that was on the car originally and the idle seemed more stable then the last time this particular one was on the car, it stayed pretty good at 900 RPMs unless I touched the throttle, then it had some problems getting back down to 900 rpms. Even though with this one it stayed at 900 RPMs and the TB angle stayed the same the ignition timing was all over the place, but I am able to do a TBA with this throttle body.

I am not sure what all this points to. Does this mean I should buy a new throttle body? Does this point in someway to some other issue with the car? I couldn't find a solid reason any where on the internet why a P1545 or a P1559 code would be thrown or any way to resolve them.

dowsett6
11-29-2010, 09:55 PM
http://wiki.ross-tech.com/wiki/index.php/17953/P1545/005445

http://wiki.ross-tech.com/wiki/index.php/17967/P1559/005465

I dont know if you have seen these or not, it might give you a little more info.

Poopie
11-30-2010, 09:36 AM
what tune are you running? Your off throttle issues are from your dv not being rerouted. Either get a forge unit that is closed at idle or recirculate it.

EuroDriven
11-30-2010, 10:10 AM
http://wiki.ross-tech.com/wiki/index.php/17953/P1545/005445

http://wiki.ross-tech.com/wiki/index.php/17967/P1559/005465

I dont know if you have seen these or not, it might give you a little more info.

This is where I look every code up. But it doesn't help for things like this....here's why:

17967/P1559/005465 - Throttle Body (J338): Fault in Basic Settings

Possible Solutions
Perform Throttle Body Adaptation

But if I have this code it doesn't let me do a TBA because it has that code...[headbang]

I will go grab the stuff I need to recirc the DV tonight so I can see if I can cross that off the list.

Will update later tonight.

nunya
11-30-2010, 10:43 AM
This is where I look every code up. But it doesn't help for things like this....here's why:


But if I have this code it doesn't let me do a TBA because it has that code...[headbang]

I will go grab the stuff I need to recirc the DV tonight so I can see if I can cross that off the list.

Will update later tonight.


Just curious, is your ABS light on as well?

--dillon

EuroDriven
11-30-2010, 11:25 AM
Just curious, is your ABS light on as well?

--dillon

Not sure, but I can check tonight. My Coolant level light is on but the sensor is plugged in on the overflow tank, and there is coolant (distilled water) in it. I need to fix all the coolant leaks before I put coolant in for good.

nunya
11-30-2010, 11:34 AM
Not sure, but I can check tonight. My Coolant level light is on but the sensor is plugged in on the overflow tank, and there is coolant (distilled water) in it. I need to fix all the coolant leaks before I put coolant in for good.

If your ABS light is on it will keep you from being able to do a TBA. You will need to unplug the power to the ABS module before it will let you do it.

--dillon

EuroDriven
11-30-2010, 11:37 AM
If your ABS light is on it will keep you from being able to do a TBA. You will need to unplug the power to the ABS module before it will let you do it.

I said I was able to do a TBA with one TB but not the other. So I am not sure if the ABS would be an issue.

nunya
11-30-2010, 11:47 AM
I said I was able to do a TBA with one TB but not the other. So I am not sure if the ABS would be an issue.

Ahh, i must have missed that. I have a spare DBC TB if you need one. Sounds like you have sorted out the bad throttle body tho.

--dillon

EuroDriven
11-30-2010, 01:00 PM
Ahh, i must have missed that. I have a spare DBC TB if you need one. Sounds like you have sorted out the bad throttle body tho.

Not quite, if you read what I posted it might be a little confusing so here:

TB which came on car:
-Giving the P1559 and P1545 code above
-Able to clear codes
-Will successfully do TBA
-will sometimes idle stably
-when at stable idle, ignition timing jumps around

TB off parts car:
-Gives P1559 code
-Code ^ won't clear
-Will not do a TBA
-pretty much perfect idle
-Ignition timing is stable and doesn't change

audikid66
12-01-2010, 12:24 PM
I'm with poopie on this. BOV + MAF = crappy idle. It has to be closed at idle or recirculated, else you'll have mixture problems.

not true i run a Tial BOV and a audi v8 maf with my tapp 630 tune and my idle is exactly like stock perfect idle.. only thing with a bov is inbetween shifts i hit a rich condition and shoot black smoke/fire out exhaust car runs perfect tho

Dan[FN]6262
12-01-2010, 12:39 PM
******I skimmed the thread, didn't really read**********

I remember seeing a picture of this, and you were running a 710n open. are you still doing that, so that its a "bov" and not a "dv"?

if you are, that is why you're having shitty idle problems. the 710 spring is not stiff enough to hold the DV closed.

if you run a BOV, you have to run a dual piston type (044) or get rid of the MAF.

EuroDriven
12-01-2010, 09:09 PM
5857;5942769']******I skimmed the thread, didn't really read**********

I remember seeing a picture of this, and you were running a 710n open. are you still doing that, so that its a "bov" and not a "dv"?

if you are, that is why you're having shitty idle problems. the 710 spring is not stiff enough to hold the DV closed.

if you run a BOV, you have to run a dual piston type (044) or get rid of the MAF.

First off I have never seen a 710n in my life....

I was able to recirculate the DV yesterday. The car runs a little better but it still almost dies at idle, but it seems to have helped in some way though.

It sounds like it is misfiring but I am getting no CEL. (Also no ABS light btw) I am thinking it is misfiring but I just haven't run it long enough since clearing the codes for the car to recognize it, but would this cause the car to be VERY weak when returning to idle? For whatever reason I keep fouling the spark plugs. They are NGK BKR7E plugs, which is what I was told would run fine, but I have to keep pulling them and cleaning them. They are gapped at 0.026", is this correct?

winston@podi.ca
12-01-2010, 10:32 PM
0.028" is what was suggested for the NGK to be gapped at.

Have you checked block 032 and see what your fuel trim says? You would have to drive the car a bit so see what the ECU wants to do for adjustment.

Dan[FN]6262
12-02-2010, 06:06 AM
First off I have never seen a 710n in my life....

I was able to recirculate the DV yesterday. The car runs a little better but it still almost dies at idle, but it seems to have helped in some way though.


lol you have never seen a factory diverter valve?

EuroDriven
12-02-2010, 07:20 AM
0.028" is what was suggested for the NGK to be gapped at.

Have you checked block 032 and see what your fuel trim says? You would have to drive the car a bit so see what the ECU wants to do for adjustment.


I will have to get the car driving, but I was cycling through the blocks looking for it and I thought I found it and it was 0, which from what I have looked up is not correct. I thought I saw it should be '1' (is this indicative of 100%?)


5857;5945503']lol you have never seen a factory diverter valve?

I saw my OEM one for about 5 mins when I took it off over a year ago...I thought the 710n was an upgrade or something, not really sure what it is. Isn't it from the TT? Why does this matter anyways when I have said multiple times it is a turbo smart DV.

.Mad Hatter.
12-02-2010, 07:28 AM
Did you swap injectors (forgive me, I skimmed the thread)? the 415s I used on my AEB were just a touch too long and they were not sealing properly into the cups threaded into the intake manifold. This was causing a leak after the TB which resulted in a slightly bouncy idle and some bucking after 5000 rpms. Worth a check maybe?

winston@podi.ca
12-02-2010, 12:11 PM
I will have to get the car driving, but I was cycling through the blocks looking for it and I thought I found it and it was 0, which from what I have looked up is not correct. I thought I saw it should be '1' (is this indicative of 100%?)


Block 032 is a % with a +/- value.

For example I wanted to test to make sure the ECU software I had was the correct file (630cc vs 780cc)

With the 630 injectors installed I got values like +22% on both main and idle trim which means I have the 780cc file.

When I installed 780cc injectors the values dropped to low single digit %'s where it should be.

It is one way to check to make sure you have the right file for your setup.

EuroDriven
12-02-2010, 12:28 PM
Did you swap injectors (forgive me, I skimmed the thread)? the 415s I used on my AEB were just a touch too long and they were not sealing properly into the cups threaded into the intake manifold. This was causing a leak after the TB which resulted in a slightly bouncy idle and some bucking after 5000 rpms. Worth a check maybe?

I saw this somewhere and was thinking about it, but would this show up as a vacuum leak? I am using Siemans 630cc injectors which look skinnier then the OEM injectors, and I know there are spacers for something with the fuel rail, but wasn't sure how to check any of this. Are these known to be too tall for AEB rails?


Block 032 is a % with a +/- value.

For example I wanted to test to make sure the ECU software I had was the correct file (630cc vs 780cc)

With the 630 injectors installed I got values like +22% on both main and idle trim which means I have the 780cc file.

When I installed 780cc injectors the values dropped to low single digit %'s where it should be.

It is one way to check to make sure you have the right file for your setup.

I will check this next time I am around the car with my laptop. Is it ok to check on a cold start? Or do I need to wait until the car is warmed up? What were some symptoms of the wrong file other then the obvious by looking at the fuel trims?

.Mad Hatter.
12-02-2010, 12:32 PM
Mine 100% caused a leak. I am not too sure about the 630cc but my 415s needed to be spaced and then I needed to replace the injector cups on the manifold to solve the problem.

winston@podi.ca
12-02-2010, 12:36 PM
I saw this somewhere and was thinking about it, but would this show up as a vacuum leak? I am using Siemans 630cc injectors which look skinnier then the OEM injectors, and I know there are spacers for something with the fuel rail, but wasn't sure how to check any of this. Are these known to be too tall for AEB rails?

You could test the sealing by spraying a bit of brake cleaner around the area and see if the car reacts to it.




I will check this next time I am around the car with my laptop. Is it ok to check on a cold start? Or do I need to wait until the car is warmed up? What were some symptoms of the wrong file other then the obvious by looking at the fuel trims?

Block 032 is stored data so you can check it with the car not running. It does reset everytime you clear the error codes so that is why I suggested you drive around a bit if you cleared the codes recently.

If you are running a file and too big of an injector the ECU might not be able to limit the fuel output and you get erratic idle. I ran into this situation when we were testing various injector sizes running a 'generic' REVO file.

EuroDriven
02-02-2011, 12:27 PM
So since I am sitting here bored, I figured I would ask a few more questions about the idle issue. I saw a thread in general B5 discussion this past week and it seems like someone may have been having almost the same issue as me. Since I ended up going through almost everything people were pointing out, could this in fact be an issue with MAF placement? I have recirculated the DV, cleaned the TB, did a TBA, connected a boost gauge to see it is pulling correct vacuum.

I originally refused to believe this is a MAF issue because the MAF is brand new and the intake setup was bought from someone who said the intake worked on a Tapp tune, BUT he had the Ford Lightning MAF. But I am starting to think now it could be how the air is flowing through the MAF.

Is there someway I can test if the MAF is the issue? (in the spring) Can I connect some ridiculous like 3 foot straight intake coming from a 90 off the turbo just sticking out of the engine bay to see if it would idle correctly? I feel like if I put the MAF at the end it would have smother airflow, and would be a clearer indication of it is a MAF placement/intake issue.


Mine 100% caused a leak. I am not too sure about the 630cc but my 415s needed to be spaced and then I needed to replace the injector cups on the manifold to solve the problem.

How do you know if it is causing a leak? Do anyone know of any threads which explain what causes this leak? What are the symptoms I can looks for?

It seems like I was eliminating things, so it is basically down to the intake configuration or the injector issue stated unless someone can think of another idea...

.Mad Hatter.
02-02-2011, 01:03 PM
Mine caused a bouncy idle and it would buck above 5000rpms. I have some custom spacers on there now and it solved the problem...it was the only issue I had during the tuning process (aka that my tuner had.)

Essentially what happens is the injector is pushed in further than the o-ring, which causes the leak.

EuroDriven
02-02-2011, 06:12 PM
Mine caused a bouncy idle and it would buck above 5000rpms. I have some custom spacers on there now and it solved the problem...it was the only issue I had during the tuning process (aka that my tuner had.)

Essentially what happens is the injector is pushed in further than the o-ring, which causes the leak.

Ah, so it LOOKS like it is on there right, but it actually has a leak?

How would I check exactly to see if that is the issue? Can I spray carb cleaner around the injectors and see if the idle changes?

.Mad Hatter.
02-03-2011, 09:57 AM
Ya, it actually gets pushed in too far so it looks good to go. Try pulling them out a bit and see if you can seat them in the cup a little more snugly.

esrokes
02-03-2011, 06:52 PM
hey what area do you live in? not sure if you scanned for this yet...

.Mad Hatter.
02-03-2011, 10:16 PM
Me? Pickering.

aaronamerica
06-27-2011, 01:28 PM
did this issue ever get resolved and what was discovered

EuroDriven
07-15-2011, 01:43 PM
did this issue ever get resolved and what was discovered

Just say this response. I never solved this. I gave up on the project and put the car in storage. I should have it in a shop I am renting in august to resume working on it. I don't think I ever checked to see if the injectors were sealing correctly, but I always saw around 20 in-hg of vacuum on the boost gauge so I figured there was no vacuum leak or anything.