1989 Audi 90 Q Idle hunting2

[Anthony Attard <ACA@nrc.gov>]

Good morning Audi fans.

I still have a slight problem with my 1989 Audi 90 Q.  I cleaned out the idle
stabilizer as was suggested, only now it will not idle when the engine is cold, and if I
turn the air conditioner on, it will drag the revs down to about 500 -- 600 RPM,
instead of the revs going up to compensate for the additional load of the air
conditioner.   Since an idle stabilizer cost so much, I hate rush in and replace it
without being sure it is bad.  

A friend has suggested that may be the brain box (electronic control Module
(ECM)) thinks there is a short in the system and I need to disconnect the ECM
and reconnect it.  Does this make sense??  if it does, were is the ECM located on
this model??   


I know this is long winded guys, but no suggestions is turned down.  
Thanks a lot.

Tony .    1983 Audi Q Turbo
               1986  4000 CS Q
               1989 Audi 90 Q