After my car warms up it starts to rev itselft to 1500 rpms then it drops back down to idle, then back to 1500 again and it constatly idles like this. Has anyone had this problem, and do you know how it fix it.

 

by the way its a zc

 

check for vacuum leaks. sounds like that to me.

 

its your vacuum lines or have u checked ur spark plugs and wires lately ? and ur pcv valve could be any of it

 

When I had my zc i had a similar problem when my tps went bad. If it is your tps it should be trowing your cel on. If your cel is on unhook your tps sensor this should steady the idle although it may be a little high and rich it will do until you can get a tps.

Charlie

 

Had this same issue when I installed my ZC. Did you bleed the coolant when you re-filled the radiator? Apparently if there's air in the coolant, air bubbles get trapped around the EACV and throws off the sensor, causing the idle to bounce. If you unplug the EACV and the bounce goes away, that's your problem.

Look at where the upper radiator hose meets the head. There's a 10mm screw there with a nipple on top...that's your bleed valve. Open it up and drain your coolant into a bucket (to reuse). Re-fill your overflow reservoir to the fill line, and start adding coolant to your radiator. Watch the bleed valve, and once coolant starts flowing from it in a steady stream (no bubbles) stop filling and close the valve. Squeeze the upper radiator hose, and bubbles should rise out of the radiator neck, allowing you to add more coolant. Continue this process until squeezing the upper hose produces no more bubbles, then top off the radiator to the neck and cap off.

Sorry if this is elementary, just wanted to be thorough.
I know some will say that draining the coolant isn't necessarry, but on mine just bleeding the coolant without draining did not fix my problem...starting completely over ensures that there's no air in the lines, period. -Z

 

I would rather say more like the tps is out of adjustment, your o2 sensor is bad or dirty, dist. timing is off or your fuel pressure is jumping around. If your tps is out of adjustment than the ecu won't know how much fuel to give the motor. If the o2 is bad than The o2 refernce signal will be off and will cause the motor to have an irregular idle. Next also Distributor timing. You can do that by hooking up a timing light. A better moethod loosen the dist. bolts and start the car up. then turn the dist slighty and slowing both ways to where it sounds like the idle smoothens out. After that check your fuel pressure it could be jumping making the car idle retarded. I had the same problem when I first did my swap. I fixed it then my tps went out of adjustment when I cleaned my TB out and the car idled from 1k to 3k!!!! it was so embarassing on the streets.... Hope that helps!

-Alex

 

good site
http://www.g2ic.com/forums/showthrea...threadid=42969