Okay, since I'm a new Prelude owner I'm going to have lots of questions, so bear with me maybe someday I'll be able to give others advice on Preludes too. (Hit me up if you're a 89-95 Ford Thunderbird SC owner! yeah!)

Anyways, my engine runs a little rough in idle when I turn the A/C on and its annoying at stop lights....of course my front motor mount is still missing since the turbo was taken out when I bought, but I think its more than that because the idle RPM doesn't kick up to compensate for the A/C draw.....any suggestions?

Thanks,

Jacob

 

TTT
I'd like to get some suggestions on this. My ITR swap is doing the same thing. It'll Idle at 1k and when I turn the AC on, it'll go down to 500 and get rough. sometimes it'll kick up, most times it won't.

 

Uh oh, in addition to my tach problem, I also get a rough idle when I turn on my A/C. Also, if the road is rough, my A/C quits pushing out cold air. Do you suppose this is an a/c problem, or an electrical problem? I've just gotten a rebuilt engine in my car and would like to try to avoid "diagnostic" fees that run up over a $1000 if I have a good starting point before I take car into a shop. Been three places already for tach problem. Suggestions welcome!!

 

First make sure your system is properly charged with refrigerant and oil, probably best to let a shop take care of that for 50 bucks or so. Then take off your eacv on the front of the throttle body, you will see a bunch of dirt and oil in it, spray it out with electical parts cleaner. find a way to turn the allen screw on the end, its a five sided allen so you'll have to be creative, but just break it loose and slightly open(unscrew) it less than 1/8 of a turn, make sure its dried out and put it back on. start the car and let it warm up until the fans come on, then turn your ac on high. If its still low then unscrew it until the idle smooths out. You should then do the ecm reset and idle relearn procedure, not sure if it's necessary.

 

Reset your base idle. It worked for me when i had the same problem.