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Discussion Starter #1
Hey guys Im taking my car Thursday to get dyno'd and the guy that flashed the computer for me to get it running didnt think the IAC valve was working. When you unplug that valve should the car shut off? Also how do I tell if it is bad? I know when you unplug it the idle doesn't change at all. Any help is greatly appreciated. Thank's in advance
 

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if you unbolt it and manually change the amount of air that the port lets it it should move the valve. I cant go into to too much detail cause i was in the car reving when we cleaned mine. but if it looks dirty in there, brake clean and a lil engine brush with work great. (DO NOT USE CHLORINATED BRAKE CLEANER. It will produce a terribly toxic gas in engine and)

The IAC is really important to the idle control and i cant imagine you wouldnt notice some problems if it wasnt moving.
 

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Discussion Starter #3
ok so if you unplug it while it's running the car will stay the same then right?
 

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97qwikcat said:
ok so if you unplug it while it's running the car will stay the same then right?
No it shouldn't. Most cars will flat out stall if you unplug the IAC, but some the idle will drop noticeably. In either case, you shouldn't be experiencing nothing happening if you unplug the IAC.
 

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Discussion Starter #5
ok then would that valve be bad or sticking?
 

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i suppose its possible to be stuck in a "middle" position, but that should pose lots of drivability issues. typically it gets stuck open and takes the rev up over 2k. Closed, it would act like there were no valve and would probably stuggle to idle. And as mentioned... with it off, there wouldnt be enough vaccuum and the car will stall.
 

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Discussion Starter #9
I had it on the dyno an everything ran smoothly. So im thinking that the valve is fine. Still pondering why when you unplug it, it doesn't stall it stay's the same and I think another guy with the same engine and car had the same thing when it was unpluged it still ran fine.
 

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Discussion Starter #10
there's no way to clean this and try to make it work is there. It's struggling to idle now so I gotta do something
 

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Ahem, i may have mistated this, unplugging the wiring will only freeze the valve in the position its at. If you unbolt it, it will immediatly stall. Even after the cleaning, mine just froze shut the other day after the car sat for 3 days. Car started and immediately stalled when it was stuck shut. Im really thinking there is no saving it totally, but its really expensive so im gonna drag this out as long as i can. BTW, there is a black paper gasket thats probably pretty worn on it, so you may wanna pick up a roll of paper gasket from autozone if you decide to unbolt it. Its very easy to trace and cut to shape.
 

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AtroXR7 said:
Ahem, i may have mistated this, unplugging the wiring will only freeze the valve in the position its at.
Unplugging the wiring should make the valve go to the full closed position if it's working properly and not binding/sticking. That is why engines will stall or the idle will drop if you unplug the valve.
 

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Discussion Starter #13
well I managed to get a new sensor free from work but it was a little different I need to cross reference the number's and make sure it's the right one. I drove it today to work with the new one on at first it wanted to stall but I wouldn't let it. Now going into 3rd gear (I beleive) its like it's dropping into neutral.
 

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master486 said:
Unplugging the wiring should make the valve go to the full closed position if it's working properly and not binding/sticking. That is why engines will stall or the idle will drop if you unplug the valve.
thats right, spring return, im sorry. I was thinking screw controlled vavle for some reason
 

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You can search. There are lots of articles on it.

I've cleaned mine several times in the 150K miles I have on my car. I still have the origional IAC. I use alcohol and a Qtip, then put a light coat of oil onthe IAC bore. after cleaning.

Symptoms of a bad or dirty IAC are stalling or high idle. You may also need to check your vacuum lines.
 
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