1991 turbo wierd idle at 1000rpm

[jimmyjoejak]

Weird Idle ~ 1000rpm
Hey guys,

My car basically idles at 1000rpm when up to temp. I did the unplug IAC valve check and it seems to be working. When the car is warm and I unplug the connector the car idle will increase to 1100-1200rpm. When I plug the connector back in it drops to about 800-900 which is within spec. The weird thing is once, I disengage the hand brake, the idle will increase to 1000rpm and then stay there. It will not drop back to 800-900rpm range whether I'm in neutral or when I clutch in when driving. Any ideas what could be causing this?

Let me know if anyone has had similar experience and how to fix.

Thanks,

Jim

[entrax]

disengage handbrake > DRLs come on > alternator needs to work harder > ??