Idle Fluxuating problem?! - Honda Prelude Forum

TheDeliveryLude · 09-28-2008, 03:15 AM

Ok so i have a JDM H22 swap from an accord si-r in a 2000 Prelude SH... well i think its an SH. Anyways right now the car is having a wierd idle problem, from start up the car will shoot to 3000rpm then instantly come down to 2000rpm and shoot from 2000rpm to 1000rpm back and fourth over and over again... even after im driving for awhile it will do it in neutral.... then if i let it sit for a few minutes, it will idle at about 1200rpm and flux between 1200-1300rpm really fast.... and will do that until i turn the car off or drive it. so i need to know whats wrong with it..... please someone help me. I really dont want to mess up my car..... but i think its a sensor.... any clue what one? does anyone know what it might be? Thanks for all your help.

an1onchigurh · 09-28-2008, 04:08 AM

i dont have an answer for you but ive had the same problem, i had a squeaky belt and i sprayed some belt treatment stuff on it and that seemed to fix it for a bit

sorry i cant help you, but im interested in finding a solution, just trying to let you know your not alone

tomhonda3 · 09-28-2008, 02:33 PM

got the same problem thinking the idle air control needs cleaned but havent gotten around to cleaning it to see if thats it

jflipwa · 09-28-2008, 06:08 PM

I agree with tomhonda3 clean out you screen on your IAC valve with carb cleaner and let it air out for an hour, your car will most likely run like garbage for a half an hour but its normal. You may end up needing to replace it, its been a problem for me before.

Qveon · 09-28-2008, 06:55 PM

To test if it is an issue with the IACV, just unplug it from the harness and start the car. If it idles (rough or smooth), then your problem lies there. If not i would shoot for vacuum leak or TPS sensor, which you can test the same way by unplugging it. One other option is to the right of the IACV there is a thing that looks like a hour glass, you can unplug the vacuum line and plug it and see if that fixes your issue. That is where my similar problem lied.

TheDeliveryLude · 09-28-2008, 10:59 PM

actually guys i had someone help me out today.... thanks alot though. it was a vacuum leak, it wasnt plugged up to the PGM-FI and/or throttle body, so i just put some rubber nipple on the 3 open vaccumm slots and it idles fine... even lower now. i hope thats all it was. it you have any questions about this PM me and ill tell you how i fixed mine.

rpwolf · 10-02-2008, 08:27 AM

did you replace or do anyting to your car prior to it idleing funny?

TheDeliveryLude · 10-03-2008, 02:30 AM

Yea... car was hit.... haha