'89 525a frequently stalls if AC to off or trans to neutral

[Gene in NC]

'89 525a frequently stalls if AC turned off at idle or trans shifted to neutral. Idle speed "increases/maintains" as it should for added load of AC or AT in gear. Stall may be more of a fuel/stumble than sharp electricl quit.

[632 Regal]

Idle control valve? (not sure if your car has one) If it does you can clean it so it moves like it should.

[winfred]

look for air leaks or a dirty idle control valve, if that checks out check out the throttle position switch