Help!

I have a 1990 Audi 100, automatic, not Quattro.

I has about 180,000 miles.

Here is the problem, when I idle, the engine idle very rough, pulsating from about 300 to 800 rpm... very disturbing.

At revs above 1200 rpm, there is no noticeable problem.

I've just changes the spark plugs and wires, and oil.

Any ideas? Need more details? Help!

Cleaning the ISV as Seattle Scott suggested. It is a very simple procedure. Remove the ISV from the rear of the valve cover and spray with liberal amounts of carb cleaner...

Also check the idle switch for loose or broken wiring...

Also try using the Misc forum or 5000/200/V8 forum next time as your 100 is slightly different than the one this forum is geared for...

Steve Ankney
88 5000
Holland, MI

if by I5 you mean a straight 5, 2.3 L engine, then yes :-).

Well, I chipped the car today and the it tells me that there is a problem with the Idle switch
(it's either stuck open, stuck closed, defective, or there is a mechanical linkage problem, or wiring problem in the idle switch area). I'm just going to take it into Metro Audi this week, and hopefully that is the problem.

Thanks for all your help