i have a h23 swapped into a 94 accord . i have a problem with my car's idle when the a/c compressor is on . the car idles fine around 700rpm when the a/c compressor is off . as soon as i turn the a/c compressor on, my idle keeps dropping below 500rpm and revs up constantly by itself . the only thing i tried so far was adjusting my idle and resetting the ecu, which did not fix the problem any . i was wondering if anyone have any ideas on what might be wrong ?

 

if anything i would take a guess at your iacv, when you turn on the ac its supposed to go up to about 900rpm or 1000rpm

 

I agree, I had a similar problem and found out the air wasn't flowing through my IAC valve. I pulled it off completely, pried the screen out of the intake port, cleaned it good with lacquer thinner (it was all caked with dirt), put it back and now no idle problem. The seal for the valve was a buck and change at the dealer. They probably won't have it in stock so order it first. Good luck

 

low idle when the AC turns on sounds like a normal occurence....even in a stock un-hybrided Honda vehicle...