What is causing my 2000 Chevy Silverado to idle high?

Tiny
PRISONER1
  • 2000 CHEVROLET SILVERADO
  • 156,000 MILES

The truck will be running just fine and without warning it will not idle down when I take my foot off the accelerator until I come to a complete stop. It will keep doing the same thing until I shut the engine off and restart the truck. I replaced the throttle position sensor without any change. It seems to do it after the truck is warmed up. I have not noticed the problem when the truck is cold. I could keep replacing parts until I go broke according to the troubleshooting book. Help!

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Saturday, December 31st, 2011 AT 10:44 PM

8 Replies

Tiny
MERLIN2021
  • EXPERT
  • 17,581 POSTS

Check the throttle plate to see if its sticking.

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Saturday, December 31st, 2011 AT 11:38 PM
Tiny
MERLIN2021
  • EXPERT
  • 17,581 POSTS

Check throttle plate for sticking open

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Saturday, December 31st, 2011 AT 11:39 PM
Tiny
PRISONER1
  • MEMBER

I took the throttle body off and cleaned it 2 weeks ago. The plate is not sticking. Do you have another solution? Before you answer, I have also considered replacing the EGR valve, the idle control sensor, and a few other parts. Please tell me you can give me something I haven't thought of.

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Saturday, December 31st, 2011 AT 11:58 PM
Tiny
MERLIN2021
  • EXPERT
  • 17,581 POSTS

Any codes? 02 sensors come online at warm up, how many miles on this truck?

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Sunday, January 1st, 2012 AT 4:59 AM
Tiny
PRISONER1
  • MEMBER

156000 miles on the truck. No codes, no check engine light, just a high idle when I least expect it.

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Sunday, January 1st, 2012 AT 3:00 PM
Tiny
HOMER1967
  • EXPERT
  • 902 POSTS

What size motor? What trans?With or without a/c?

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Sunday, January 1st, 2012 AT 5:20 PM
Tiny
PRISONER1
  • MEMBER

6 cylinder 4.3, five speed, with a/c

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Sunday, January 1st, 2012 AT 10:49 PM
Tiny
HOMER1967
  • EXPERT
  • 902 POSTS

I would suspect a faulty idle air control valve. Although there are t.S.B's for this vehicle to have the pcm re-flashed. But I would try a new i.A.C. Valve first.

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Monday, January 2nd, 2012 AT 1:56 AM

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