Ok I read my service manual and idled my car to spec. BUT when I put the A/C it drops it down to where I know and can feel it needs to be idled up. Is there another setting I need to change (Like fast idle) or something to keep it at the correct idle speed even when the A/C is on ?
Thanks !

 

THE ECU SHOULD adjust for the a/c being by moving the idle up. I could check to ensure that the ICV is working properly

 

You could also check if the AC is overcharged or the compressor is going out. Maybe the compressor is too much drag compared to what it's supposed to be?

 

also u might not be getting the proper a/c input signal if so most likely wiring problem,,or you could have a faulty ecu

 

Sounds like an alternater problem. I had the same problem with mine and I put a new Alt on and it stopped.