Truck has high idle and gets higher when it warms up? Gets up to about 1600rpm
5 Answers
Dirty or faulty idle air control valve can cause this issue.
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A vacuum leak can also cause it. I would check that first.
Thanks it's my buddy's truck! Yah we used carb cleaner and sprayed around to check for vaccume leaks got nothing.
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Is that valve in the TB?
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Yes. Can't seem to get a picture to down load. Sorry. Google this :: 1999 sierra 1500 idle air control valve --- it will give you a picture of one.
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