Help - a/c & idle

[Steve Manning <stephenm@ix.netcom.com>]

I am completely frustrated by trying to fix the following problem on my 1988
90q, so any help is appreciated:

- 90% of the time, car at idle, turn on a/c, idle stays constant (800-900rpm).
- after car has been in stop & go traffic for about 15-30 minutes, the idle
suddenly drops to about 500rpm.  Turn of a/c, idle is fine.  Turn back on,
idle goes to 500rpm (car shakes very badly).
- after car has been turned off and sat for awhile, start car, run a/c.
Idle is fine.

*Something* either temperature or time-related seems to destroy the signal
to compensate the throttle for the additional a/c load on the engine.  ISV
is only about 6 months old.  No apparent vacuum problems.  No other symptoms.

I would appreciate any ideas....thanks everyone.........SLM

Steve Manning:	stephenm@ix.netcom.com (Metro D.C. area, USA)
....Mainly Mopars; also '88 90Q/'90 200tqw/'88 635csi; other stuff
......BMWCCA #93xxx, FCA, USCC, QCUSA, Wagons of Steel, etc.