have you checked the fuses for the cruise control?

when the AC is turned on, the car will idle a little bit higher. Is this what you are describing or is it reving high then falling low, high, then low, etc...? When do you turn on your AC, right after you start the car or later down the road?

 

Fuses

I have checked the fuses under the hood and the only ones that were blown were the auxiliary fans I think fuse 5 and 18... It doesn't matter when I turn the a/c on the engine revs real high and stays there. never drops until i put the car in gear.

 

dude you are in SD is cold as a fridge up there,and we are going into the winter.what are u doing still using the A/c? lol, i suggest you check you sensors on the throotle or your ICV

 

i dont think the cruise control has any fuses from memory.. i retrofitted it into my car and didnt use any i dont think. as said above, define 'high' idling

 

Cruise control

It rises past 3000 RPM's as if I was just sitting on the gas pedal. And actually it was 60 degrees here today lol.... But I will definitely try your suggestions. I have the haynes manual and plan on tracing the wiring diagram to try every component. please keep helping me lol... ill keep everyone posted

 

It rises past 3000 RPM's as if I was just sitting on the gas pedal. And actually it was 60 degrees here today lol.... But I will definitely try your suggestions. I have the haynes manual and plan on tracing the wiring diagram to try every component. please keep helping me lol... ill keep everyone posted

im not sure what it is that makes the car idle higher once the A/C is engauged, but i would guess its that computer or whatever that is the issue

 

High idle - A/c



My 1990 E30 does the same thing. i have swapped out the idle stabilizer and ECU. My mechanic is stumped. Let me know if solve this mystery.

 

E30 high idle a/c

I fixed mine. It turned out to be the throttle position sensor. It had no continuity when the throttle was at idle. As such, the ECU did not engage the idle stabilizer to control the speed.
Pull the connector off and check continuity between the middle spade and the left spade. It should have continuity at idle. If not, it probably requires replacement. Only about $60

 

I have a 1990 BMW 325i i just got it a couple of days ago, and the first two days i was driving it fine, then IT HAPPEN when i go to stop at a light or stop sign and through it in neutral my RPM goes up and when i though it in first still stopped it goes down but it causes me to stall out....but then it will stop and be normal again but this has happen to me a couple of times now already and its embarrassing when i stall out at a light and have people yelling at me, so im having the same problems....

 

was this the same problem you were having when you got yours fixed with with your throttle?