the first minute when my g/f starts her car the idle goes up and down from like 1 1/2 to 3 rpm! anyone ever have this prob w/ there prelude (it is a 94S) what could it be??? idle speed motor??

 

Bump!

 

Does it stay there? Is the engine light on? You may just need to adjust the throttle cable a little

 

IT JUST DOES IT FOR A MINUTE OR 2!! no dummy light on or anything!

 

Well my car does the same exact thing but it goes from 1 1/2 to 2 but not for a few sec but for like mins. I dont know what u got done to ur car and all but my car is a 92 lude-S and i just got intake and exhaust but it idle like a b!+(# in the mornings and after a cold start. I was told that it does that because the cars comp. is searching for something that was prob. taken out or missing so it copensate from idling from 1 to 2 or 3 but i heard that nothing is really wrong with it but it does get annoying.... well i hope that helps u any...

 

Maybe it's your fast idle control valve?

 

Fast idle valve?

 

its the fast idel valve when you first start it up when its cold, its nothing big , but if you start to adjust it for the winter time, itll be different for the summer. you might need to adjust it again.

 

Sorry, fast idle CONTROl valve.. it's sits under the Throttle body.

 

try the idle engine temp sensor, right beside the thermostat, might be bad. you can unplug it use some wire to bypass it and see if that fixes it and if it does theres your prob