I searched and found most rough idle problems start with the IAC, along with other things..

My problem is the car idle's completely okay w/o the A/C on. Once the A/C is turned on, BOOM, the idle starts jumping -- down to about 400 then up to 600 (numbers are approximate, but it just keeps speeding up then slowing down) and back and forth... does this sound IAC related? Thanks!

 

Yea,it may be a dirty/malfunctioning iacv,it might also be a bad maf sensor.

Maf thread link--> http://forums.maxima.org/showthread.php?t=524493

 

Does it slow down when the compressor is on and speed up when it is off? Could be that the IAAC A/C idle up solenoid isn't working.

 

Well, like any A/C kicking on, at first it brings the idle down.. but - then it starts bouncing back and forth/idling up then down..

I thought it could be the MAF too, but it was replaced 40K miles ago (not sure if thats a long time or not...) and runs perfect w/o the A/C running... thats why I'm confused...

 

Its ur fuel injector cause i had the same problem thats why i loved driving with the ac on in the city. But after i replaced all of them never the same problem.

 

Why would it run fine w/o the A/C -- and to also add to it - it runs fine after a few minutes of driving or warmup. It will still swing some, but not near as much....

 

As long as we are talking about the IAC, is there any advantage to removal and cleaning of this part?

 

Sure!

 

lol exactly... but that doesn't help my situation..lol

 

Easy - the normal range of travel of the IAC valve when the motor is warm is quite small - when the motor is cold/AC is used, and when the IAC is required to move more than the normal range, gunk can prevent/delay its correct and timeous operation - so go clean it anyway.

 

Well, I'll clean it when I install the intake spacers... will report back if it doesn't help and go from there