Engine not idling properly, throttle non-responsive

[boy412]

I did not have time to pull codes this morning but my car has never done anything like this in 11+ years and 196,000 miles. Hopped in this morning and the car was stuttering, sort of like what you would experience with a bad coil pack. Then it almost totally died...at which point the revs would go up and down in 1-2 second bursts. I tried blipping the throttle but the throttle was completely non responsive.

CEL came on, along with the traction control light and EPC light. I was running late and hopped into my E30 () and have been thinking about this all day long now. OCD is fun, isn't it?

I'll post up codes when I get home but does this sound familiar to anyone? The only thing that has changed recently is new BKR7e plugs (about a week ago). Going to check those too.

[Knives1010]

Without codes as you know there's no real way to tell but just gut guess is either MAF, throttle position sensor, or the throttle body didn't align properly like it is supposed to on start up. I know that those three lights all together lighting up DOES mean something significant I just can't remember for the life of me what it is at the moment.

[Coors]

Probably your CPS. Pull codes.

[customa4]

Maybe intercooler hose popped off. The throttle not responding is the tricky part.

[boy412]

Coil packs (07k's) have about 10,000 miles on them. Just seems like yesterday but it was almost exactly a year ago! Getting old sucks.

Will pull codes as soon as I get home.

[boy412]

Maybe intercooler hose popped off. The throttle not responding is the tricky part.

I've had that happen to me before and its nothing like this. With a loose (or popped off) boost hose the car would start and idle fine, but fall on its face under boost (or lack thereof). This is something completely different. The throttle bit is what has me concerned. Hoping its not a bad ECU or something like that.

[customa4]

The reason I mention it is because I had my front clip off at one point and forgot completely to put the intercooler hoses back on to the hard pipe down the bumper line. I had symptoms exactly like yours where it was in dying mode and struggled really hard to run. Only different part was it reacted slightly to throttle movement. Still a few other culprits involving fueling that could be involved, maybe throttle body.

[b6_quattro]

sounds like a bad MAF to me. unplug it and see if it runs better.

[B5audiRS4]

sounds like a intake leak, bad maf, bad coil, bad injector. any of these can cause that problem, does it surge ?(rev every second or so)

[boy412]

does it surge ?(rev every second or so)

Kind of...

[boy412]

Its looking like the throttle body itself. I can actually HEAR it failing when I turn the key to ON. Not the normal throttle body adaption noises...but an electric crackling sound. Pulled codes and got LOTS of them (not surprising):

Ignition coils:
P0351
P0352
P0354

Misfires:
P0300
P0301
P0302
P0304

And throttle:
P0638 - Throttle Actuator Control
P0221 - Throttle pedal position sensor/switch B
P0121 - Throttle pedal position sensor A Circ.

Cleared those and the P0638 code came back. Not surprising given the sounds it was making. I may take a look at some of the local pick-n-pull yards this weekend or I may just replace it with a new one. Or maybe one of my mid-Atlantic buddies has a spare one? You fockers are all probably at Waterfest though.

Original one lasted 11+ years and 196,000 miles! Not bad.

[boy412]

Well it doesn't seem to be the throttle body. Tried another one today (bought a used one) and the symptoms are the same. Also tried unplugging the MAF (long shot) but that had no effect. Didn't have time to pull codes again but I'm willing to bet they will be more or less the same as what I posted above. I'll bang on it some more when I get home this evening. This does NOT feel like coil packs or a loose/ blown boost hose.

Any other thoughts? Driving around without A/C is getting old.

[Knives1010]

I would say try the lower throttle sensor, it may not think the throttle is at the bottom because of the bad sensor. Thus sending more fuel than it needs and drowning out the system. I would think that that would also cause surges as well but I don't actually know.

[boy412]

Interesting. I will check it out. Looks like the whole pedal and electronics module is sold as a single part, which kind of sucks.

[SlickFix]

Also tried unplugging the MAF (long shot) but that had no effect.

Wait, if you unplug the MAF, it should run worse. If there is no difference after unplugging the MAF, then the MAF itself is bad.

[old guy]

Wait, if you unplug the MAF, it should run worse. If there is no difference after unplugging the MAF, then the MAF itself is bad.

Not necessarily. If the MAF sensor input and the rest of the fuel related inputs are close to the base maps you may not even be able to tell that you unplugged the sensor. If the ECM is making significant adjustments away from the base maps then it can make a noticible difference.

[Molotov]

Just jumping in this one after a quick read. Did you check the ECU/relays? Not to jump to conclusions, but I had an intermittent throttle issue that eventually turned into no throttle input response. I had originally thought the pedal assembly wasn't working. I used VAG-COM to check accelerator pedal input and it checked out as good. I looked in my ECU box and it had water in it. Replaced relays and cover but the issue persisted until I swapped over my Maestro tuned ECU.

[SlickFix]

Not necessarily. If the MAF sensor input and the rest of the fuel related inputs are close to the base maps you may not even be able to tell that you unplugged the sensor. If the ECM is making significant adjustments away from the base maps then it can make a noticible difference.

Well shoot, I sit corrected, then. I thought that unplugging the MAF sensor was supposed to make your engine idle like crap. Sorry for the misinformation.

[boy412]

I've been meaning to check the relays under the ECU. Something in the back of my mind told me to check that first and I just haven't had time to check yet.

I hope it's not an ECU problem...I'm sure Tapp will want $$$$ to license an additional ECU.

[boy412]

OK so the three relays sitting under the ECU are NOT sitting in a puddle of water, nor does it look like water has ever found its way in there. That's good I guess! Need to do a little cleaning:



I realize this doesn't mean the relays are OK...but I'm not sure how to go about testing them (other than just replacing them). I have a multimeter so if someone can guide me on testing them I'd really appreciate it. I don't want to just start throwing parts at this car but if thats what I have to do then so be it.

I'm also having trouble FINDING these relays on VagCat. I have some part numbers but wanted to verify them against ETKA.

[boy412]

Not necessarily. If the MAF sensor input and the rest of the fuel related inputs are close to the base maps you may not even be able to tell that you unplugged the sensor. If the ECM is making significant adjustments away from the base maps then it can make a noticeable difference.

You can unplug the MAF on this car and it runs fine. Certainly nothing like this...

[boy412]

Took a short video of the issue:

http://www.youtube.com/watch?v=yCLylHQRO5g

No MIL or other indicators until I stabbed the throttle @ 0:45. Then blipped the throttle again @ 1:00. The sound isn't that great but you can hear what the motor is doing. This actually was one of the better start attempts. Cleared the codes again and the P0638 is coming back each time...twice in fact! My VCDS Lite software isn't working right now (generic OBD-II cable) so I've been reading and clearing the codes with Maestro Flash.

(if I film this again I'll make sure the tach is visible the whole time)

[boy412]

Tried new "219" and "373" (now "645") relays. No dice. Waiting for a new accelerator pedal assembly from Europa...hope to have it sometime early next week.

[boy412]

Man...this forum really is kinda dead, isn't it?

[old guy]

Hi Eric. Sorry to hear about your issues. I spent an hour or two running down your codes and symptoms and I am struggling to come up with a suggestion that you haven't already tried. If the pedal assembly doesn't cure it (and I don't think it will) I suspect you may have a corrupted ECM tuning file.

Good luck!

[boy412]

Hey Fletcher - Thanks for chiming in here. You KNOW I appreciate it.

:)

I'm pretty certain that the pedal assy. is not going to do anything either...but I am just approaching the situation as if I were a technician and didn't know this car. I have the advantage that its sitting in front of my house...and have another car to drive in the interim! If the pedal assy. doesn't fix it then I'm going to assume there is either something wrong with the wiring running to the TB, or the "used "TB" I've installed is also bad (unlikely but possible). If its the tune itself I can re-flash the file pretty easily. Its easy enough to try and doesn't cost me anything (for once). If its the ECU itself that is going to be an adventure.

Thanks again man...

[coltspeed]

This may or may not help. But I have had a similar experience on a nissan primera. Turns out the battery was stuffed. There was enough power to start the car and drive it but, it would only rev to 3k and drop to 1k and climb to 3k again and drop again etc... I couldn't figure out what was going on and it ended up being really simple that I wouldn't have thought to check

[boy412]

I'm dubious that it would be the battery causing these types of symptoms, but its something easy enough to test. Thanks for the post.

[boy412]

I am still wondering about the condition of the throttle body. I bought a used one on eBay and it didn't solve the problem, but its making the same sounds as the one I pulled off. I shot another short video which captures the sounds pretty well (ignore the birds chirping). Does this sound like a normal TB adaption to you? Sounds sketchy to me. I appreciate the input...this car is making me very sad right now.

http://www.youtube.com/watch?v=KX5VGRzslps

I have another TB sitting here on my desk...box new, still sealed. I was going to return it to recoup the expense...but I'm willing to try it out. Just don't want to eat another $200 if I can avoid it.

[customa4]

I wish I could help. I actually had a spare TB that was in working condition that I allowed a noob on here to use for testing. Thing is, he tested with it, then kept it, without actually paying for it... Texted him, messaged him, and sent him a PayPal invoice, no dice. Got burned for trying to help out. It's not really about the money, it's the principal.

[boy412]

No doubt...that's no way to behave! He'll get his someday. Karma is a bitch that way.

[old guy]

You video sounds a lot like my TB. I get a high pitched whine for exactly 30 seconds and then the throttle plate blips once.

[boy412]

You video sounds a lot like my TB. I get a high pitched whine for exactly 30 seconds and then the throttle plate blips once.

Do you hear that crackling sound though?

[boy412]

Pulled #1 plug today and it was wet and looked pretty fouled:



Yanked them all:



...and replaced them with new BKR7E plugs (kept them gapped @ .034 this time). I have to admit I was hopeful the car would fire right up and run normally but alas.

[csosnowski]

I did not have time to pull codes this morning but my car has never done anything like this in 11+ years and 196,000 miles. Hopped in this morning and the car was stuttering, sort of like what you would experience with a bad coil pack. Then it almost totally died...at which point the revs would go up and down in 1-2 second bursts. I tried blipping the throttle but the throttle was completely non responsive.

CEL came on, along with the traction control light and EPC light. I was running late and hopped into my E30 () and have been thinking about this all day long now. OCD is fun, isn't it?

I'll post up codes when I get home but does this sound familiar to anyone? The only thing that has changed recently is new BKR7e plugs (about a week ago). Going to check those too.

Its looking like the throttle body itself. I can actually HEAR it failing when I turn the key to ON. Not the normal throttle body adaption noises...but an electric crackling sound. Pulled codes and got LOTS of them (not surprising):

Ignition coils:
P0351
P0352
P0354

Misfires:
P0300
P0301
P0302
P0304

And throttle:
P0638 - Throttle Actuator Control
P0221 - Throttle pedal position sensor/switch B
P0121 - Throttle pedal position sensor A Circ.

Cleared those and the P0638 code came back. Not surprising given the sounds it was making. I may take a look at some of the local pick-n-pull yards this weekend or I may just replace it with a new one. Or maybe one of my mid-Atlantic buddies has a spare one? You fockers are all probably at Waterfest though.

Original one lasted 11+ years and 196,000 miles! Not bad.

I just finished a timing belt job on a 99 A6 2.8L Friday and the car wouldn't idle, with my foot on the accelerator pedal it would blip the throttle itself in bursts. I was lazy and didn't want to scan for codes right then so I waited until yesterday and re-adapted the throttle body with VCDS and voila, idles perfect.

Have you been able to perform the basic settings on the throttle body? It seems obvious I know, but I didn't think I would have to manually adapt the throttle body on this A6 either.

[boy412]

I haven't been able to use VCDS Lite (licensed version, with a generic OBD II cable) since I installed my PPD a while back. Even in "maintenance mode" I can't seem to get it to communicate with the ECU. Maestro Flash has been working fine and that is what I've been using to pull codes. I suppose its worth temporarily removing the PPD out of the equation and trying to adapt the TB via VCDS. I wish I knew someone nearby that had a "real" Ross Tech cable so I could test that.

If you aren't familiar with the PPD this is what I'm talking about:

http://www.3zero3motorsports.com/sto...rs4-a4-s4-audi

[customa4]

If it's easy to take out temporarily, definitely worth a shot. Not sure if you mentioned it but did you try to do the throttle body reset without VCDS?

[old guy]

Do you hear that crackling sound though?

Whine yes, crackle no. I didn't pick up on the crackle until I just now when I listened with headphones instead of the subpar laptop speaker.

[boy412]

I feel like we are making some progress here. So I pulled my PPD out of the loop and now I can use my VCDS software again. Yay! I'll need to ping Sean on that and see why I can't use the cable/software with the PPD in place. That's going to be a real problem!

So fired up VCDS and tried to to a TB adapt. This is what I got:



Now that VCDS is working I pulled codes. Lordy!

VCDS-Lite Version: Release 1.0
Sunday, 27 July 2014, 13:22:24:44682
Control Module Part Number: 8E0 909 518 AK
  Component and/or Version: 1.8L R4/5VT     G   0003
           Software Coding: 0016701
            Work Shop Code: WSC 79929
5 Faults Found:
17966 - Throttle Actuator (G186): Electrical Malfunction
        P1558 - 002 - Lower Limit Exceeded - Intermittent
17987 - Throttle Actuator (J338): Adaptation Not Started
        P1579 - 001 - Upper Limit Exceeded - Intermittent
17967 - Throttle Body (J338): Fault in basic settings
        P1559 - 008 - Implausible Signal
17579 - Angle Sensor 2 for Throttle Actuator (G188) Implausible Signal
        P1171 - 008 - Implausible Signal
17950 - Angle Sensor 1 for Throttle Actuator (G187): Implausible Signal
        P1542 - 008 - Implausible Signal - Intermittent

Cleared them again and the P1559 code came back. Sooooo given that this TB is making crackling sounds (like the old one mind you) and all this other shit...do we think that replacing the TB is the correct course of action?

[customa4]

http://wiki.ross-tech.com/wiki/index...7/P1559/005465
http://www.audizine.com/forum/showth...p-P1545-Errors

You followed this procedure for resetting?

[Select]
[01 - Engine]
[Basic Settings - 04]
Group 060
[Go!]
It should say "Basic Settings: OFF" on the top of your screen.
Click [ON/OFF/Next] to turn on Basic Settings.
It should now say "Basic Settings: ON" on the top of your screen.
Once you do this you will see the top right display say ADP RUN. The TB adaptation is being done as soon as you switched basic settings on. You will see the values change and hear the TB cycle for the first few seconds then it will stop. Leave it in Basic Settings for about 30 seconds.Click [ON/OFF/Next] to turn off Basic Settings.
It should now say "Basic Settings: OFF" on the top of your screen
Click the [Done, Go Back] button and you're all set.
Be sure not to touch the accelerator and make sure the engine is NOT running when you do this!

Throw the other throttle body in and try it again to see if the same error comes up. If it does I would say the throttle body isn't the problem and might be something electrical in the area. The crackle is the one thing that would make you believe it's something mechanical and not electrical.