I just encountered this problem. The night before it idle fine. Today I start the car (cold) and the idle was kept bouncing between 1000-2000 rpms in a continuous cycle. I drove around for 30 mins (warm)... still bouncing.

Possible culprits?

BTW: No check engine lights. The night before it happened I was driving in unusually heavy rain.

 

Your Idle Air Control valve has failed. You might get by with cleaning it but it's easier to just replace it. Do a search for that and you will get plenty of results.

 

Check for vacuum leaks & try cleaning things before you waste money throwing parts at your car. It could be a small vacuum leak in one of your hoses. If that was the case replacing your IACV wouldn't help you.

Accord FAQ's check out the link below. It has some good info to help with a surging idle

https://honda-tech.com/zerothread/1844067

 

I just started it back up this morning. It had a steady high rev (1.8k rpm) for about 5 minutes. Then rpm started jumping again. I parked it went to store to buy carb cleaner, came back out and it steady at 600 rpm to eventually idling back to normal around 770 rpm. So far it's good again.



Modified by mxl360 at 3:29 AM 9/8/2008

 

ghost knows whats up.

vacuum leak! i would recommend cleaning FITV,IACV and throttle body, check your vacuum lines, there should be a diagram for them under the hood.
an easy way to check for vacuum leaks is to get a can of brake cleaner and spray it around the vacuum lines, intake manifold lower and upper gaskets, throttle body gasket, IACV and FITV, with the engine running. If there is a vacuum leak then you will hear the engine bog down a little and then pick right back up to where it was idleing.

 

I had the exact same problem with my 98 civic ex.. I thought is was a vacuum leak but it actually was the Idle control valve.. Very easy to replace and not to spendy. But just in case I would run a test for a vacuum leak.