What are the main causes of flux idle? my car does it randomy its a 93 eg hatch with a jdb d15b and sometimes it'll flux idle then stop, its really random... Ive cleaned the ICV numerous times now and that fixes it for like... 3 full warm ups then after that it'll do it again... and ONLY when its FULLY warmed up. any info on this would be very helpful as i want to smog the car asap thanks!

 

Fast idle valve under the tb, check that there is a white screw that backs out sometimes. If it is just screw it in. I had this problem and it was air in the coolent, check that too

 

ok, i'll check that later, thanks! yeah i already ran my car for about an hour with no radiator cap xD just little white bubbles now...

 

See #13? That's the fast idle valve (also known as FITV by some). There is a removable plate on the back side of the FITV down and to the left of #2. It's held in with 2 phillips screws. You can take one screw out, and just loosen the other and see if the big plastic white disc inside has backed out or not. I usually screw it all the way in, then back it out maybe a 1/4 turn. You can also dab a touch of Hondabond just inside the FITV where the threads are for the plastic disc to keep it from backing out again.

Also noteworthy is that if the FITV plate being backed out is the issue, and someone has tried to fix the idle by adjusting the idle mixture screw, throttle cable (ie ghetto rig), etc. then fixing the FITV might actually result in a crappy, low idle in which case adjustments will need to be made to the idle mixture screw.

 

What may do it, at least it did it in my miata, is a partially blocked egr valve. It recycles the exhaust into the intake so it can get silted in and block airflow. I'd say the other guys that posted probably have more experience with civics so try their ideas first and see if that helps.

 

Well My idle adjustment screw on the throttle body has to be all the way in so it doesnt idle too high lol.... its ALL THE WAY in and it sits at like 1000... and i know thats not right, along wit the flux idle could the FITV be the problem for that as well? and also does anyone have a link to cleaning the IACV, Ive cleaned it but ive never taken it apart and cleaned it, or do I just spray carb cleaner while its together and let it dry?

 

His Civic does not have EGR. Good looking out though.

That is exactly what I was saying about how once you fix the FITV then the car probably won't idle until you make the adjustments at the idle mixture screw. See IF the FITV is backed out then it will let too much air in, which at first causes a high idle - people try to fix this by screwing the idle mixture screw in until the idle settles down.

As the FITV becomes more backed out it goes from simply having too high of an idle to an idle fluctuation.

I'd start at the FITV, then work your way back to the idle mixture screw.

Personally I don't mess with the IACV unless it's throwing a check engine code 14 for idle air control valve. If the IACV is truly your problem then it should throw a code. The FITV will NOT code.

 

Wow thats really helpful, thanks! I had code 5 and 14 at one point then reset the ecu 14 went away and i found out that the vac line on the map was totally disconnected xD