I've got a '91 Honda Civic DX w/z6 swap converted to multipoint and jumped to OBD1 w/chipped P28 ecu...

The car has ran fine for the last year with no issues. Till recently (about a month ago) when I would start the car up the idle would start surging till the car was warmed up than would stop and run a low steady idle. Well that went on for the last couple months till just last week when the damn thing started the surging idle problem non stop.

Ive owned other Hondas in the past that had similiar issues but was cuased by the IACV (idle air control valve) all of which through a CEL (check engine light) for a code 14.

My current car is not throwing any codes and is still idling this way. Could it still be my IACV? Is there anyway to fix the IACV without replacing it? I was told you could but Im not 100% sure?

I was also told that it could be my chipped ecu and that the program CHROME sometimes makes cars idles surge? Again not 100% sure just what I heard.

Can anyone please help me and clear some info up for me?! It would be greatly appreciated! LOL

 

First off I would recommend trying to borrow somebody's stock p28 and see if that makes a difference. If it's been working fine for the past year and recently started surging unexpectedly then I'd lean more towards a vacuum leak of some sort.

 

possibly. try disconnecting an reconnecting the iacv. if tht doesnt work. when is the last time you replaces our fuel filter? a cloggd fuel filter can also cause rough idling. my hatch was idling at 2krpm at a cold start jus recently. i replaced my filter. an havnt had problems since

 

It runs even worse when you disconnect the IACV! Obviously lol

And Ill check into the fuel filter. I've never replaced it.

Does anyone else have any suggestions?

Anyone heard of fixing the IACV or cleaning it?

 

Take off the iacv spry parts cleaner in it to clean it out if that don't help try taking off the fitv uner the tb and clean that out and tighten the white plastic screw inside off search on hear pretty much info on both of them and hot to do it gl