Re: ISV valve

[Richard Beels <beels@technologist.com>]

I would start checking the vacuum hoses for splits/leaks.

At 11:44 AM 9/25/1998 ,  Alex Tarlowski was inspired to say:
>  I drive a 1990 Audi Coupe Quattro 20V with 200k km, and I have been having 
>  some idle problems lately which I am almost certain are due to the ISV 
>  valve. The initial fault was a no idle what so ever condition with no
other 
>  performance changes above idle, this occurred immediately after about 150 
>  km (90 m) of 150-180 km/h (90 m/h- 112 m/h), driving on an open highway 
>  with the oil temp approaching but not exceeding 130 C (266 F). After 
>  reading some background engine problems advise on the 20V coupe quattro 
>  page I removed and cleaned the ISV and it worked fine, for about 20 K of 
>  city driving. The idle problem then returned quickly but not all of a 
>  sudden.
>  Next day I soaked the ISV in degreaser for about 4 hours and the car again 
>  worked fine for about 50 K of city driving, but performance is now 
>  beginning to show tell tale signs of fading, ie it has to hunt a bit for 
>  900 rpms when I let of the gas pedal and it occasionally stalls.
>  I am going to give the valve one more soak followed by a good blowing with 
>  an air hose but my question is this, is this valve on it's last legs or 
>  might there be something blowing in from the crankcase breather that's 
>  plugging it up, or might there be another source for this fault?


Cheers,
	Richard
	88 90Q - <insert pithy witticism here>
	88 Golf GTi - PRO Rally