Re: idle problems

[jgraham1@erols.com]

Mark Zvolanek wrote:

> Gday q-listers
> Please help me with this one. I am new to Audi I had this one for few
> months now.
> I am still having idle problem on my '91 Audi 90. So far I have
> cleaned
> ISV, replaced crankcase breather hose, checked idle switch.
> When the car is stationary it idles well, when I pull out oil dipstick
> it
> recovers in a second. When I am in traffic not going more that 40km/h
> or
> so and when I stop it still idles well, i.e drops down to 800RPM and
> never below. But as soon as I go faster (approx more that 50km/h) and
> then stop idle falls down to ~600RPM and then it slowly moves up to
> 800RPM or it occasionaly stalls. Even if I try to assist it by
> depressing
> gas pedal slightly does not help, it seems to wants to get up to
> 800RMP
> by itself.
> Only thing I have not changed yet is oxygen sensor. Would OXS be
> causing
> this? When I bought the car all was well. Would OXS fail from one day
> to
> next, or does it fail slowly? Any recomendation on which one to get,
> OEM
> or universal.
> Where would be the most obvious place to check for vacuum leaks. Could
> it
> be a air leak that occurs only when engine is under load?
> Someone recommended me to check tps malfunction, what is tps?
> Thanks for reading up to here.
> Any help or comments would be greatly appreciated.
> MarkZ

 One more check. The spark plugs, are they OEM three electrode type?

John.
1990 QC