ludeh22bb2

okay i have a 1993 Honda prelude with a h22a1. for some reason the idle revs up and down. I've checked for vacuum leaks but can't find any. One time i tried turning down the idle and that made it go away for like 4 weeks but now its back. I also cleaned the fast idle thermo calve and that didn't help either. I have searched for this problem on all the forums but cant find a definite answer. can some one help me?

here is the link for the video of what it does -

S-LudeDan

Have you tried cleaning the IACV - Idle Air Control Valve?

Clean throttle body?

When was the last time you had a tune up?

Use search function on this forum and also search Google. There is a ton of info out there. What you have can be a numerous number of things.

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minilogoguy18

IACV is more than likely bad, they wont even throw a code most of the time, find someone with an older honda and try swapping, an accord one will work. If the coolant level is good and no vac leaks then the idle valve for sure, gonna cost like close to $300 for a new one.

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New Formula Red 93 BB2: JDM OBD1 H22a/T2W4 Accord Euro R transmission

S-LudeDan

do you think it's worth that he tries to clean his old IACV first? Instead of buying another one?

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ludeh22bb2

yes recently i have done a tune up and cleaned the throttle body. the reason i cleaned the thermo valve was because it starts to do it once the engine warms up but that didnt help at all. i actually have a 1994 Honda Accord as well and it does the same thing but its automatic so it only does it in neutral or park. ive tried searching hours on end on google but cant seem to find a definate answer, i know with idle problems there isnt always a definate answer but if this also happens to my accord then it has to be a fairly common problem that someone else has fixed. so i will try to clean the IACV and go from there. thanks. ill keep you posted.

S-LudeDan

yeah try that, but keep in mind if that doesn't work that means you might need a new IACV.

Did you screw in that platic piece in the FIT Valve? It should be screwed all the way in.

Also EGR valve and port cleaning may also improve idling issues. The carbon build up in EGR ports sometimes causes these problems. I would look into that as a last resort, because this requires the most work as far as valve maintanance and other idling problem solutions.

Believe it or not, air bubbles in the cooling system may also be a culprit. If this is the case, the entire system needs to be flushed and refilled.

Just tackle one thing at a time and eventually you will find the solution.

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minilogoguy18

I said he should try a known good one before anything, cleaning rarely works unless it every once in a while has a shudder. If it full on bounces all the time then it's usually shot.

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New Formula Red 93 BB2: JDM OBD1 H22a/T2W4 Accord Euro R transmission

ludeh22bb2

Okay so i tried cleaning it and it didnt help. So i will try to swap a known good one. which engines would have an interchangeable one with an h22? Just an h23?

s-lude dan - i did screw in the plastic piece when i did that and i will try to clean the EGR and ports.