Mechanics

I HAVE A . I HAVE A PROBLEM WITH IT IDLING TOO HIGH. WHEN THE ENGINE IS WARM, IT STILL IDLES AROUND 1400 RPM. I READ THAT THIS CAN USUALLY BE SOLVED BY CLEANING THE IACV, BUT I FOUND THAT AFTER I CLEANED IT, THE PROBLEM STILL PERSISTED.

1996 Toyota Corolla • 164,000 miles

I tried unplugging the MAP sensor as well, and the idle dropped while running. I just wasnt sure if this meant the MAP sensor was bad or if it was a normal occurance. What else can I do to further troubleshoot this problem?
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Dansfraz
December 9, 2011.




When did this start? I would clean/check IAC valve as that is the air supply for idle. Any vacuum leaks can cause high idle also.
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Tiny
Fixitmr
Dec 9, 2011.
The car has idled high as long as I have owned it. I bought it used back in the summer and it has done it ever since. I cleaned the IAC valve and it didnt seem to change at all. What is the best way to check for vacuum leaks?

Tiny
Dansfraz
Dec 9, 2011.
You can do a visual for broke/split cracked/loose hoses. You can spray a flammable substance like spray start around gaskets and parts to see if engine speed increases. You can do a smoke test and watch for smoke to be sucked in to leak. Also IAC valve may be bad so cleaning it dont help.

Tiny
Fixitmr
Dec 9, 2011.
As suggested, I replaced the IAC valve and the idle improved dramatically. Now it idles high for 5 min or so when cold and around 1100 when warm, much better than the 1600-1800 it had began to idle at.

Tiny
Dansfraz
Aug 11, 2012.

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