# Idle Air Control Valve



## Sprout98 (Jan 3, 2008)

Hello,

Recently, I had my car diagnosed at a garage, and they said 1 of 3 parts are bad, either the TPS, MAF sensor, or IACV. I've already replaced the TPS and when I disconnect the MAF, the car stalls (so it's doing it's job). I think I've got a bad IACV. If the car is idling in Park, and I disconnect the IACV sensor, what should happen?


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## jdg (Aug 27, 2009)

Sprout98 said:


> Hello,
> Recently, I had my car diagnosed at a garage, and they said 1 of 3 parts are bad, either the TPS, MAF sensor, or IACV. I've already replaced the TPS and when I disconnect the MAF, the car stalls (so it's doing it's job). I think I've got a bad IACV. If the car is idling in Park, and I disconnect the IACV sensor, what should happen?


Nothing...should stay idling at the same rpm (give or take a few)...

However...before you disconnect it, make sure everything is off, A/C, headlights, blower, radio, everything...
Then, disconnect the IACV, let it idle for a little bit, then, as fast as you can, turn it all on, A/C, headlights, blower motors, pump the brakes, everything.
The car should die (or at least start stumbling) because the computer can't compensate for the extra load on the engine.

And if those clowns at the 'garage' couldn't figure out if the problem was either the TPS, MAF, or IACV, then you need to be looking for another garage.
A TPS is very easy to troubleshoot with just a multimeter.
A MAF (as you've figured out) is just as easy to troubleshoot.
An IACV, as I've described above, is also easy to troubleshoot, and likely carboned up and needs a good cleaning.
What's the name of this 'garage', so others can be sure to avoid them like the plague?
And besides, you never did give any mention to your actual 'problem'...
And how many threads do you need open on the same subject/problem?


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## Sprout98 (Jan 3, 2008)

jdgrotte said:


> Nothing...should stay idling at the same rpm (give or take a few)...
> 
> However...before you disconnect it, make sure everything is off, A/C, headlights, blower, radio, everything...
> Then, disconnect the IACV, let it idle for a little bit, then, as fast as you can, turn it all on, A/C, headlights, blower motors, pump the brakes, everything.
> ...



JD,

Sorry if you have beef with me opening a new thread, but isn't that why the Forum exists? For help? You could just opt not to reply. :balls: You answered my question...the info helps me...let's leave it at that?!


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## jdg (Aug 27, 2009)

Sprout98 said:


> JD,
> Sorry if you have beef with me opening a new thread, but isn't that why the Forum exists? For help? You could just opt not to reply. :balls: You answered my question...the info helps me...let's leave it at that?!


I could opt out, but when the answer is so obvious, especially when those procedures are listed in whole lot of books, not the least of which might be one of those Chilton's or Haynes manuals...jeeze...
Ya know... You're right... You are absolutely right. Whenever an answer to a question is painfully obvious, so obvious that my wife can usually answer the question, I won't!


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## dfresh (Jun 19, 2004)

I just recently threw a code P0505 which is the IACV. The symptoms are on warm starts it struggles to start right. On cold starts it cranks fine. I may try the cleaning. Anyone know p/n for new filter in case it tears? Or p/n for new IACV?


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## dfresh (Jun 19, 2004)

I cleaned my IACV this weekend. It was all gunked up. Cleaned inside and out. Idle problem went away. Starts right up and doesn't stall anymore.


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