Backfires

2000 CHEVROLET SILVERADO
89,000 MILES • 7.4L • V8 • 4WD • AUTOMATIC
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DAMION4XX
  • MEMBER
  • 1 POST
I bought a 'the truck listed above k3500 dually and now it won't go over 2,000 rpm (at all), backfires and loses power if I push the gas to hard. I had the knock, cam and crank sensors replaced and the crank relearn can't be done since the truck can't hit 4,000 rpm. It sat for a good two or three years and was put back on the road in 2016 (at that time the truck acted like the rev limiter was set to 3,000 rpm and would backfire over that). The timing, rotor cap/ button, plugs/wires have been fixed/changed also. The truck also did not have catalytic converters either, someone told me back pressure could cause my issues also. It has been suggested that either it is my distributor itself or a fuel pressure issue, but I have no idea. This is so far above my pay grade and I'm absolutely lost. any help at all would be greatly appreciated and thank you.
Aug 24, 2019 at 2:10 PM
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STRAILER
  • CAR REPAIR CONTRIBUTOR
  • 54,189 POSTS
Hello,

This is common when one of the valve springs breaks. I would remove both valve covers and use a flashing to check the coils of each spring. Here is a guide to help:

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

Please run down this guide and report back.
Aug 26, 2019 at 3:01 PM
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