idle speed on my 1996 GMC SIERRA pickup is very high , what can cause this?

1996 GMC SIERRA
100,000 MILES
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HIVES
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  • 1 POST
Its a 5.7 engine and the idle speed is very high always and theres nothing sticking that I can see.
Nov 17, 2011 at 12:08 AM
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ASEMASTER6371
  • CAR REPAIR CONTRIBUTOR
  • 52,796 POSTS
check the throttle body gasket. common failure that causes a high idle condition. Also check the EGR valve here is a video to show you how.

https://youtu.be/DqUCbbKdWf4

Check out the diagrams (Below). Please let us know what you find.

Cheers, Roy
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Nov 17, 2011 at 12:13 AM
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
I had this problem It was the EGR valve.
Nov 17, 2011 at 12:14 AM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.