85 urq stalling mystery

[GaidosIII@aol.com]

All,
 I am still looking for any suggestions as to why my quattro dies when
idling. It only happens after I've been driving along and push in the clutch
to come to a stop. If I turn on the a/c the problem seems to go away. In
general the problem only seems to occure when the engine is warmed up.
 Can anyone suggest where I might start out to debug this problem? I'd like
to have it solved before begin some much needed repairs to the car.
Thanks everyone
Anton