A/C On = erratic idle when stopped...

[Chew_12]

Alright I just noticed this once I turned on my A/C not to long ago. When ever I have the A/C on, the idle will be about 600 then drop to about 400, almost stalling the car. I notice this when the car is stopped in Overdrive. When I am in reverse it normally does stall the car. When the A/C is off the idle is normal. I had the A/C rebuild about 2-3 years ago, but im suspecting it might be the compressor? What do you guys think?
Thanks

 

[Gonefishin4lyfe]

Mine does the same thing. I think what the problem is, is just the idle is low enough that when it kicks on the a/c your engine isnt idling high enough and its causing the rpms to drop. The a/c will cut off the rpms arn't high enough. I had an aftermarket a/c put in a ranger and it did the same thing until I adjusted the idle, but the X doesnt have the same setup the ranger had so I am not sure how to turn up the idle a little bit.

 

[TPLYNCH]

Start with the IAC. That controls idle. Clean it and see if there is any change.

 

[monkeydude3]

Seems like the iac to me, because when your compressor kicks on the computer should sense that and kick up your idle to compensate.