Fluctuating Idle

[carotman]

Well I got a fluctuating Idle problem

here's what it does:

I step on the gas and the revs go up no problem.

When they go down, they drop too low and go back to normal in like 0.5 secs.

SOmetimes it drops even below the 500 rpm mark.

So far I changed my IAC valve (2 times with used ones) and my fast Idle valve....

Any idea what could it be?

I'm suspecting my EGR or maybe a leaking gasket.....

The problem goes slooooowly away as the car warms up... if I drive the car for like 1 hour... the problem is almost absent....

[ACCORD EX]

i had the same problem when cold ! now it disappeard after i changed my wire ! don't know if that's related !?

MIKE

[tyne89]

lol i have kinda the same problem but on whens it been hot out. mine will actually stall out at time so i think it might be something more.

[carotman]

figured out my problem by myself :)

Thanks for the replies tough.

[ACCORD EX]

Originally posted by carotman
figured out my problem by myself :)

Thanks for the replies tough.

and what was it !?

MIKE

[carotman]

Well it's simple but complicated at the same time.

My idle was a bit high and I decided to lower it a little. I turned the screw until it came to the idle specs. The thing is, I lowered it too much and the ECU didn't like that, so it sent a signal to the IAC valve as I was turning the screw, completely fooling me.

So when I stepped on the gas, the revs went up to problem and the IAC valve closed. Then I let off the gas, the throttle closed, the revs dropped too much and the ECU was opening the IAC valve to compensate... but the ECU would have a 2 seconds delay which caused the fluctuating Idle..

The correct way to adjust the Idle is to unplug the IAC valve so the ECU cannot compensate. You set it at 800 rpm and everything is fine.

[ACCORD EX]

thank god i have carbed ! :D no damn ECU controling the shit !

MIKE