bent valve or internal problem? Symptoms

[WHITECELICAGTS]

My car has been idling really low for the past month. It goes down to 400 rpms. It never did this kind of thing before. It will also do it after the car is completely warm. You will come to a stop somewhere and the car starts shaking cause the rpms go so low. I cleaned the throttle body and MAF sensor last week and that didnt help. I am gonna check spark plugs tonight and do a compression test.

Anyone have any other suggestions for me?

Seems to maybe be an air or fuel problem. The thing is, im not getting a CEL at all from this low idle.

[Blue Bomber]

Could be your IAC valve. Have you had any problems with the RPMs bouncing from 1-2k at idle?

[WHITECELICAGTS]

I had that before, that use to always happen to me.

Where is this valve?

[Blue Bomber]

The valve itself is mounted on the bottom of the throttle body, but the air inlet for the IAC is inside the throttle body. Check this out:

http://www.newcelica.org/forums/showthread.php?s=&threadid=123383

[pro-style-gts]

It very well could be bent valves also. You need to do a compresiion check on all of your cylinders. When you do this you need to turn the engine 4 revolutions per cylinder. Your psi should not vary more than 20psi between cylinders. If it does you most likely have a bent valve. Also listen to your intake, does it sound like it is spitting?

[WHITECELICAGTS]

I did the compression check tonight.

Looking at the car from the front

left to right the cylinders read like this

200-200-210-200

Is there a reason the one is higher than the others?

My car has over 80000 miles on it...

[TRlPPlN]

Originally posted by pro-style-gts
Also listen to your intake, does it sound like it is spitting?

what do you mean by spit?? like its making popping noises??

[WHITECELICAGTS]

Today on the way to work. I had to stop at a few lights and stop signs. All of a sudden the rpms would jump to like 4000 and back down again...for like 30 seconds at a time...i was like wtf is going on. People kept looking at me like wtf is this kid doing. Would this be the IAC valve being shot?

The intake is making a spitting sounds now too...

let me know what you guys think. Im gonna make a video of it tomorrow and post it here. It sounds horrible.

[Blue Bomber]

Originally posted by WHITECELICAGTS
Would this be the IAC valve being shot?Yes. It usually averages revving from 1000-2000, but my friend has had it as bad as constant revving at 6000. :eek: Did you clean the IAC yet?