DillyD

I have a 92 prelude with a Jdm h22a swap. I am not really sure which h22a it is i do know that it is a jdm tho. Anyways, my problem is this. Sometimes when my car is warm the idle creeps down till it almost stalls and sometimes does. Also, when it is acting weird if i give it alittle gas and let off it will idle correct then creeps down again. If i press the gas and level it off and hold at 2500 or 3000 or where ever. It will actually creep down if I just hold it still. If I even twitch the pedal it will jump back to where it was or alittle higher depending on the amount i pressed the pedal. I have replaced the IACV, fast idle, map sensor, and messed with the tp sensor. Still can't get it to idle right any ideas? PLEASE ANY HELP WOULD BE AWESOME. It sucks to have to start you car at a red light about every 4th light! Also, my ecu was chipped when i bought the car but it was chipped in like 2004-2005 and the problem started about late 2007 or 2008 could the ecu be the problem? Like i said it doesn't do this all the time. PLEASE HELP!!!

BDM

There is a screw on the top of your throttle body. Try tightening it as tight as you can get it. That's what fixed mine. =] It's worth a try.

nus_dogg

Try ^^^ that or try a friend's p13 ECU.

meanshyguy

Make sure all your vaccum hoses on your IM are going where they're supposed to, that fixed my problem.

jonbar87

sounds like a bad IACV. You have an FITV which controls idle at cold startups, and an IACV that controls the idle once it's warmed up. If you take the IACV off (front of the IM) there will be a screen that is usually dirty and causes the problems that you're describing.

DillyD

Yeah i just replaced the IACV last week in an attempt to fix this problem. Nope not that.

DillyD

Yeah that has been done too lol. I tried to adjust the TPS in hopes that that might be the issue, but it wasn't. I adjusted the screw as well still Idles bad sometimes i actually think i made it worse messin with the TPS. I mean i got my stock idle spec where it is supposed to be but the idle still goes bad when ever it feels like it. Anything else i might try?

withoutlimitslude

throw the ecu away and get a modded p28 with a h22a program if you cant afford a street tune at the least...i had a similar problem and when i switched ecu's problem was solved!! hope that helps

DillyD

You know i actually have another ecu for this car in the closet. I'll have to pull it out and plug her up and see what happens. Where might i find one of these modded p28 ecus and the h22a program you speak of? I am not up to date on ecu tuning really i stay to d@mn broke

DillyD

I dont think it is a vacuum issue cuz it doesn't act up all the time. I reason if it was vacuum it would always be messed up. I feel like its electrical. I thought it was a sensor but i have change all of them?
Totally STUMPED

DillyD

Ok so today i messed with the throttle screw a bit and the tps some more i think i got rid of the dying but now it seems to lope. not like when your iacv is bad but it revs slow slow then its like it cuts out makes almost a bump sound and the rpm fall rapidly back to normal then stops suddenly. Then it starts over. Pretty much the opposite of the problem i had before. GRRRR I think the TPS is out of wack anyone know how to adjust that thing?

DillyD

Ok, so i tried an unchipped p13 ecu today it did about the same sept when i romped on it the thing trough a knock sensor code. Can't deal with that. Anyone know how to tune your intake? I think that is my issue. A mixture of the TPS the throttle adjustment screw and the IACV.

minilogoguy18

Have you read the faq thread on idle surge yet? Do you have the helms manual? Knock sensor code just means that the ECU can't find a working knock sensor, sounds like your 'chipped' ECU is haggard.

DillyD

The ecu that throw the knock sensor code is a stock P13 ecu that has not been chipped. And everything i read says IACV but i know for 150% sure that it isn't that i have change it twice now in the past month. NOT THE PROBLEM. I have had the surging issue before and this is not that surge. Oh another thing i can't even find a knock sensor on this engine. Not sure it has one. Anyone know about JDM H22a knock sensors?

minilogoguy18

The knock sensor is easy to find, on mine it was blue(old H23a1 it was green) and it's like dead center on the back of the block, the plug going to it will just have a single red/blu wire. Have you tried adjusting the fast idle valve yet? Even though it's for cold start ups it'll still cause a bounce when warm and a high idle (like 2k) when cold.

DillyD

yeah thats where the book says it it but it doesn't seem to be there. no hole for it or anything. Yours is like right under the fuel rail huh? and yeah imma try and just bypass the fast idle