gents:

I am piecing back together a 95 ex civic coupe junkyard retrieval. Going pretty well, but have a problem with a surging idle 1000-2000 rpm regardless of hot or cold. No codes from ecu. Replaced EACV to no effect. May have a vacuum line mixed up, but who knows. One suggestion is PCV is shot, have not tried this yet.

Any suggestions?

northwoods (of minn)[/align]

 

i had this same problem on exact same car. took it in and it cost me 75 bucks for them to figure out that there were air bubbles in my coolant, so try that just flush your coolant and then refill with bleeder bolt open until coolant comes out then shut it. it fixed mine.

 

Good idea about bleeding the cooling system of possible trapped air. Bleeding without flushing should be sufficient.

As mentioned, you might also have a vacuum or intake air leak. Check all the hoses and connections for leaks, including those from the PCV valve.

Another possibility is a dirty EACV/IACV. Try cleaning with carburetor cleaner. See DIY by GReddy_Civic.

 

Idling too high is usually a vacuum leak or the throttle plate not closing fully. There is also a mechanical temperature controlled "fast idle valve" built into the throttle body.

 

I had a similar problem with my 2000 civic except mine was also stuttering while i drove at cruising speed. Another possible place to check would probably be the throttle position sensor.

 

check the throttle body if its working properly or not

 

thanks for the replys! I did check for vac leaks, air in the radiator, clenad off elec connectors, then checked the FICV. May have the culprit here. Pulled the duct off the intake and found suction in the idle air port. Manual says this indicates a FICV failure, and I plan to replace it. If the running engine is warm and I plug the port with a spare finger shouldn't the problem go away? Tried this and it keeps surging.

So, what do y'all think?

Northwoods

 

great suggestions, guys!

Got around to checking a few more things tonight. COme to find out the throttle body gasket is sucking air - as it should be - there's no gasket there! carb cleaner sure works for this bit of detective work. Now, to find a cheerios box and a lttle silicone....

northwoods

 

throttle body gasket was the problem! 5 bucks for parts. Will be modding this car for high efficiency now that it runs good.

many thanks to all for the great suggestions!

northwoods