backfires through throttle body

1996 CHEVROLET CHEYENNE
200,000 MILES
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DARRYL10
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  • 2 POSTS
5.7 liter 350 chevy pickup cranks but wont start backfires through throttle body while cranking it over?
Jan 30, 2012 at 6:33 PM
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DOCFIXIT
  • CAR REPAIR CONTRIBUTOR
  • 18,828 POSTS
It sounds like the engine has lost timing like the timing chain has jumped. Here is a guide to help you check the timing chain.

Here is a guide and the timing chain diagram below so you can see whats going on.

https://www.2carpros.com/articles/engine-backfires-while-running

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

Cheers
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Jan 30, 2012 at 6:40 PM
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DARRYL10
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  • 2 POSTS
Yep the timing chain was gone! I replaced it but the engine had bent valves so I junked it, thanks for your help though.
Jan 30, 2012 at 6:46 PM
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DOCFIXIT
  • CAR REPAIR CONTRIBUTOR
  • 18,828 POSTS
Use 2CarPros anytime, we are here to help. Please tell a friend.

Cheers
Jan 30, 2012 at 6:48 PM
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.