Well I replaced the fuel filter yesterday and I couldn't believe that the oem filter was still in there, stamped 11/97. Ok I sort of can with Audi's lifetime garbage. Anyhow that thing was plugged like no other. Took about an hour for the change and it was a little tough. Local mechanic quoted me 3.5 hours. Ummm, no. Anyhow the car responds 10 times better now but I still have the drop in idle. It hasn't stalled yet, but when I come to a stop the idle will sit at around 1k then drop to 400 and jump to 800 and rest, with a little bounce of 50 to 100 rpms. I don't know still but I'm planning on checking the icv and throttle body.

 

Car finally threw a cel. P1504, so I will be replacing my IAC valve and I hope this takes care of it. Think I will also order some new vac lines as well .

 

Interceptor I'm having hte same problem, where abouts in Michigan are yoiu from? I'm having a tune up done, it could very well be the fuel filter which could be clogged considering without being in gear and driving there's not much fuel being pushed thru your lines but going into neutral and the RPMs drop alot of that fuel flow is cut down and it's not enough to keep the engine running. Dfinitely get a tune up and change the fuel filter, hopefully that should work. Ill keep you updated, as I'm getting one soon.

 

I am north of Mt. Pleasant.
Me and a buddy will be first cleaning the ICV and throttle body first this weekend to see if that will work. I'm still trying to confirm if there is any gasket or something on the throttle body? From the write-ups it looks like I don't need to worry about needing a vag-com or gasket.

 

rough idle usually on the 12v is the ICV valve, it just gets covered in oil spray. to make sure its actually faulty check with am ultimeter, is should be between 7-11 ohms.

 

Holy s@#$. Ok. The throttle body was awful. Both pcv tubes or whatever they are called, (the black flex tubes) were so gummed up with froth and oil gunk that they were blocked almost completely. Tested the ICV and it was only at 1 ohm. Not good, but my buddy has a tester that is not the greatest. We cleaned everything up including the ICV and the car is back to normal. No more idle surges and stalling. I will give it a few days though and if it acts up again then I'll order the ICV. I would suggest this to everyone as a normal maintenance routine.

 

Awesome news! This is exactly what I wanted to hear, how long did it take for you to take the ICV out, clean, and reinstall? Would you by chance have any writeups/diagrams for removal?

 

I would say a couple of hours for every thing icv and throttle plate and vac hoses and such. My buddy does most of the work but I try to help and learn.
http://www.audiworld.com/tech/eng.html
Look for cleaning the throttle valve and icv.

The flex tubes (pcv) were awful to get back on. I cleaned them like no other and I think the o-rings swelled making it a pain.
I'm still betting on the icv to conk out but so far no stalling and crazy idle. Car does still shake a little on idle but idle holds pretty steady. I soaked the icv in maf cleaner for a while and sloshed it around then let it dry followed by wd 40 into the inspection port. It's also good to use a mechanics mirror and spray into the throttle body and get all the gunk. Open the flaps up a little and clean as well. By the way I left it on.
96 I would really suggest doing this if you can or have them do this. Like stated above this seems to be a problem.

 

Thanks man, I greatly appreciate the info. I'll be tearing out the ICV and throttle body this weekend. I'm going to completely disassemble the throttle body and sand it just a bit, a friend of mine (great mechanic) will be helping me so with the two of us wrenching it shouldn't be bad.

 

Nice results there. Have the same problem. It has irradic idle, doesn't sound any good.. And it usually lives its own life when I put it in reverse when it's cold, gives throttle by itself etc.

If anyone can make a picture guide for cleaning the ICV, that would be great!
And also, cleaning the throttle body, isn't it a hassle + ineffective if you don't actually take the top off? And you can't re-use your gaskets, can you?