hey i have a 92... or 93 civic hatch and whenever the engine is cold (ie when i start it in the morning) the motor revs from 1100-2500 until the engine warms up. its really pretty frickin embarassing considering i live in an apartment and my ghetto civic sounds like its out of breath at 7 in the AM... i already tried replacing the IAC and that didnt work. if i dont have an intake on, would this cause this wicked idle? or else what else could it be?

 

you dont have an intake? you runining it strait open?

 

if you dont have an intake pipe or nothing thats probably it. good luck

 

not having an intake on there has nothing to do with it. since its a HIGH idle it sounds to me that there is a possible vacuum leak on the intake manifold side. another problem found on higher milage vehicles is that when there is too much carbon build up inside of the intake manifold and the sensors (MAP, IACV) or whatever you may have. it effects the way the car idles, and also the gas milage.
hope this helps a lil.

 

actually i have a custom intake on it.... that is.... a nylon and a rubberband. ghetto i know. it does sound like a vacuum leak, it revs until the engine warms up. after that it stops and drives perfect until i cold start it again... i already tried a diff IAC... didnt work.. any other ideas?

 

did you put a NEW IACV on? that REALLY sounds like your problem... i just replaced one on my sedan

 

you ever try disconnecting the negative battery connection for a couple of minutes then plug it back on and start the engine...then see if it still idles funny...mine used to do that until i did that...the only mod i had was a catback exhaust...i heard its called resetting your ecu? but i dont know...it worked for me