High Idle Than Bam Irratic Idle

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MKy car used to do this and it turned out to be a vaccuum leak. Have you pulled the Intake manifold? You might want to consider replacing the IM gasket, that is what fixed mine.
 
yea, after my 'r' manifold swap, i could never get the throttle body to seal right. i tried over torquing and ended up snapping a stud.

get some throttle body cleaner and spray around suspicious areas, if your idle changes, you've found the culprit.
 
Originally posted by Accordturbo94+Oct 29 2003, 12:32 AM-->
Originally posted by Jim Truett@Oct 28 2003, 11:53 PM
Accordturbo94
@Oct 28 2003, 10:33 AM
anyone else got a theory

I have had a vacuum leak in the brake booster cause the same symptoms. Disconnect it, and plug the vacuum port that feeds it, and see if your problem goes away.

hey that sounded pretty good at first but.. than i thought about it.. it wouldnt make it rev so high right away when i start it..

Yes it might. Remember the ECU won't correct for a high idle right away. It takes a few seconds. Once a high idle condition is found, the ECU will try to reduce it by reducing the orifice size of the IAC valve. If the vacuum leak is too great, and the engine is getting too much air at idle from a vacuum leak, the ECU may oscillate the IAC valve trying to reach proper idle mixture. Anyway, try it. All you have to do is remove one vacuum line. It is a hell of alot easier than pulling the throttle body or IM.
 
Originally posted by Jim Truett+Oct 29 2003, 10:25 PM-->
Originally posted by Accordturbo94@Oct 29 2003, 12:32 AM
Originally posted by Jim Truett@Oct 28 2003, 11:53 PM
Accordturbo94
@Oct 28 2003, 10:33 AM
anyone else got a theory

I have had a vacuum leak in the brake booster cause the same symptoms. Disconnect it, and plug the vacuum port that feeds it, and see if your problem goes away.

hey that sounded pretty good at first but.. than i thought about it.. it wouldnt make it rev so high right away when i start it..

Yes it might. Remember the ECU won't correct for a high idle right away. It takes a few seconds. Once a high idle condition is found, the ECU will try to reduce it by reducing the orifice size of the IAC valve. If the vacuum leak is too great, and the engine is getting too much air at idle from a vacuum leak, the ECU may oscillate the IAC valve trying to reach proper idle mixture. Anyway, try it. All you have to do is remove one vacuum line. It is a hell of alot easier than pulling the throttle body or IM.

Right again.. I havent tryed it yet! I AM going to tomarrow! But when ive started it before the revs never went so high.. to get it warmed up! Im talking 2900rpms when i start it up when the motor is cold!
 
I dont know if this makes a diffrence! but my idle speed on my throttle body is all the way closed! I had to close it before to bring the idle down to the right level. and it ended up being screwed in all the way!
 
So yeah I played with it more tonight! I checked the vacuum line to the brake, that was fine. I rechecked timing thats good. I tested all the lines again! That looks good. when I unplug the IAC the idle drops to about 1100 and just barely bounces up and down. I just dont know what to do anymore!
 
man i am having the same problem yes.i pulled the plug for my IAC and my car cut off,so i am wanderin g now if that is bad,but a friend of mine did the same to his and the car cut off also,so i dunno man, i really amm thinking abotu everything but i am jus as baffled as you yes
 
Yeah fuck hondas! I dont know why I even mod cars, there slow as piss anyways! I have an 8 second hayabusa! As for why this car is a POS... Im thinking thats its the unit on the throttle body thats sensons when to give you more throttle when you start the car for say cold weather.. because it revs very high when its cold untill its warm! Im going to throw my accord throttle body on it and see what happens! im out of ideas.. its weird no one else has had this problem! Or knows WTF is going on! Im pissed can you tell?
 
Fixing an Irratic Idle

this is so common there is an article on this forum already. It's how I fixed mine.

If you want the idle to stop revving so high, either clean the IAC you have w/ throttle body cleaner not just air or get a new one.

This wouldn't be so frustrating if you followed the advice you're asking for.
 
Hey could it be my fast idle thermo valve! I took it off an you can see its loose inside and rattles! When i shook my accord throttle body i didnt hear the same noise!
 
Alright I changed it and it still is doing the same thing! I noticed by just listening to my car that when i put my ear but the intake manifold.. i can her a click click sound! I just cant figure it out... could it be my intake manifold? i just dont know why it goes click click click.. its rather loud so im doubting its my injectors. Now to clear things up hear my car didnt start sounding like this untill i went cruizing in another town that has some nasty roads for cruising. And im going to be honest as dumb as it is i didnt put the brace that goes on the motor and the intake manifold.. I dont know if this could have caused my intake manifold to become loose or not! but wouldnt i notice a huge leak of coolant out of intake manifold if this was the reason? or be able to hear the thing leaking and not just clicking? thanks for any info
 
dude i know this was suggested before, but the intake manifold gasket caused EXACTLY the same thing on my prelude
 
the gasket is urethane.. it shouldnt be bad. Its the hondata intake manifold gasket. Was yours leaking? maybe my intake manifold is just loose
 
Well Ill be damned! But 500hp h22 blew the welds off the intake manifold. No just kiddin but i started takeing my stuff apart to see if it was my intake manifod! Sure shit enough every single bolt was broken off the top of the manifold! Im actually glad about it. at least now i figured out the problem! note to self honda makes the brace for a reason (PUT IT ON) well its another lesson learned! thanks guys!
 
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