High idle running AC

[kikkoman]

My car idles around 1k but when I turn on the AC it jumps up to 2k and stays. What's weird is the idle stays high even when I turn the fan to off position until I switch AC off. I know running the AC in most cars slightly raises the idle but not this much. I haven't tried running the AC all year but we are now hitting almost record highs (>100) and it's just too hot to drive w/o it.

[bmwstephen]

i think its weird that your car is idling at 1k without AC

[Sagaris]

It sounds like what happened on a Digifant2 VW I had. When I switched the A/C on, the ECU would try to compensate for the load that the compressor would normally make on the engine. I think it is ICV related. unplug the ICV , start the car, and see if it still does it. I advise against unplugging and plugging in the ICV with the ignition on, on some EFI systems this can really piss off the ECU.

[brody]

There are A/C on Idle maps, it sounds like you are having issues with your ICV, or that you throttle plate is too far open mechanically at rest.

[kikkoman]

Thanks for all the responses. It sounds like everything is pointing to the ICV (again!) which might be. I had a fluctuating idle at startup (bounce bewteen 1-4k for few seconds before settling) about a year ago which also pointed to malfunctioning ICV so I had it replaced with a different used one which temporarily stopped this but it kind of started doing this again recently. I'll see if simply cleaning it will fix it and if not temporarily replace it with one that's known to work correctly and see if the problem goes away.