Bouncy Idle

[[HIREVZ]]

hey boys n girls i have a 1991 honda integra and me n a friend reset the ecu today (pulled out the fuse and disconnected battery) and when i had put everything back together again i let the engine idle for 15 mins. When the car had started up it was fine n then 10 mins later after letting it idle it started to bounce from 1000 too 1500 and now everytime i drive and i let it idle it just bounces from 1000 to 1500.... just wannt to know how to get rid of this and if its something major

[[HIREVZ]]

PS i checked my spark plugs and there pretty new i only put them in a month ago and also i did do a search and nothing similar had come up

[seihoa]

after u let it idle did u go for a short normal drive (without thrashing) ?
cause your suspose to let it idle and then take it for a normal drive for awhile and let the ecu gather data again...

but then again could be something else = /

[[HIREVZ]]

yeah went for a short drive and it still does that
5 hours later

[kyle]

The only thing that causes a hunting idle is a vacuum leak. The air leak causes the idle to rise, so the ecu cuts fuel. The revs then drop back down so to prevent stalling fuel is added again and up it goes again. This cycle continues to repeat.

Interesting you say this happened after you reset your ECU. You didnt touch anything else when you did it? Knock any vacuum hoses off your plenum by accident?

[Slow96GSR]

^ What he said.

[EuroDude]

lol my civic was doing that hunting thing. It wasnt a vacuum leak.

I cleaned the throttle body, cleaned the IACV filter, and screwed in the FITV valve, problem solved.

(I think it was the FITV causing it).

[JohnnyVtec]

']hey boys n girls i have a 1991 honda integra and me n a friend reset the ecu today (pulled out the fuse and disconnected battery) and when i had put everything back together again i let the engine idle for 15 mins. When the car had started up it was fine n then 10 mins later after letting it idle it started to bounce from 1000 too 1500 and now everytime i drive and i let it idle it just bounces from 1000 to 1500.... just wannt to know how to get rid of this and if its something major

How ya goin m8,

Un-plug the power from your iacv then start the car. you will most likely realise it no longer surges when idling. If that's the case, take off the iacv and clean it out with any *NON* solvent cleaner you can find. then put it back on. and plug it back in. If the problem then persists. Pull it back off and use a block-off gasket. you'll have to cold start it yourself until you get a replacement iacv.

Hope that helps. Cheerz.

[[HIREVZ]]

where do i find this IACV and FITV

[[HIREVZ]]

The only thing that causes a hunting idle is a vacuum leak. The air leak causes the idle to rise, so the ecu cuts fuel. The revs then drop back down so to prevent stalling fuel is added again and up it goes again. This cycle continues to repeat.

Interesting you say this happened after you reset your ECU. You didnt touch anything else when you did it? Knock any vacuum hoses off your plenum by accident?

na mate didnt knock anything off.. well i dont think so it was just a simple fuse out and disconnect battery

[EuroDude]

IACV http://www.ozhonda.com/forum/showthread.php?t=4693&highlight=IACV
FITV http://www.emotors.ca/Articles/97.aspx (FITV is under the throttle body opening where the air intake pipe attaches.)
Throttle http://www.ozhonda.com/forum/showthread.php?t=35488

[kyle]

....It wasnt a vacuum leak.

I cleaned the throttle body, cleaned the IACV filter, and screwed in the FITV valve, problem solved.

(I think it was the FITV causing it).

Well the fact the FITV wasn't screwed in, air was getting in un accounted for, thus you had a vacuum leak.

[[HIREVZ]]

hmm okay i disconnected the IACV and the igly is steady now but engine lite is on just need to know what to clean it with and if i have to take it out

and how much does a new one cost?

[EuroDude]

Use Carby / Throttle Body Cleaner the clean out the black gunk form the IACV. I doubt you need to buy a new one, hopefully it just needs a clean :thumbsup:
And clean the throttle body while you are at it, especially the idle bypass pipe/section.

[[HIREVZ]]

thanks people ill clean it tonight hopefully all goes well!

[Boban]

A friend spent 350@honda to fix his integra. Don't know what exactly was the problem but they ended up taking off the intake manifold and fixing something there. Hope your's isn't as bad

[kraiye]

had same probs on my civic. iacv was a piece of cake to remove and clean :thumbsup: and after that it idled fine