Idle fluctuation problem

My car has had a idle that fluctuates back and forth from 1500 to about 1800 rpm. This has been going on since I put a 93 integra gsr motor in my 94 civic. My car also has some headers, a better intake, and aem camgears, but I dont see any of those things causing an idle problem, besides maybe the cam gears. The car drives fine once moving, and everything else is working just fine, including all of the sensors for the idle, which have all been checked against working sensors. I can't figure out how to fix this and neither can three of my mechanic friends. Has anyone encountered this problem and fixed it, or have any ideas of how to fix it? Thanks.

Stupid question... did you reset your ECU after you did each mod? If not... yank the fuse or disconnect the battery and let her sit for 10-15 minutes and then attempt again. If it aint that, I dunno ~ someone else will know though!

all of the B-series VTEC motors fluctuate rpms during idling a little bit here and there. It's nothing to worry about, more temperature control than anything.

have you tried checking for vacuum leaks?

I had the same problem on my accord, it took about two years of replacing individual pieces and finally I replaced the idle control valve. There is one sensor that plugs in and a small coolant line that runs from the intake maniflod to it. I think it's on the back drivers side of the intake manifold on the B-series.

I had the same problem , and it turned out to be a loose vacuum tube going to my fuel pressure regulator. Check all vacuum tubes!!!

Is this problem only when idling like at a dead stop? cause ive had this problem and i also had a problem like that when driving.

The problem when driving was caused by my tranny but i couldnt figure out my idle problem, so just check my hoses too?

My friend's Civic did that after a swap and he was told the idle control valve was bad. We replaced it and it stopped.

Originally posted by kaisersozi
and everything else is working just fine, including all of the sensors for the idle, which have all been checked against working sensors


obviously people didnt see this part, but anyways.

option 1
like i said before check the vacuum lines. basically for a quik check just put your finger over the little hole directly inside the throttle body. if the rpm goes down your cool, if not, you got a vacuum leak. then start clamping off lines and marking them to route out the leak. i would still check every line itself though for safety sake.

option2
like what was said before about the fuel pressure regulator. and if it is functioning correctly itself regardless of vacuum.

option 3
did you check the injectors, fuel filter, and fuel pump? a serious drop in fuel pressure at idle could make it fluctuate

option 4
have you checked the ignition coil or all the ignition components at that? even a shot plug wire can screw you.

option 5
check the timing

option 6
when you installed the cam gears did you use the marks to correctly identify tdc and bdc etc..?

Because of a password problem my name changed to kaisersozi63. I checked everywhere for vacuum leaks and found none. I am at college right now and will not be able to mess with my car more until I go home, probably next weekend. I will try the other stuff that was suggested and then and post whatever the results are. Thanks for the help.