Engine misfire

1999 DODGE RAM
250,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC
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CHARLES STEELE
  • MEMBER
  • 37 POSTS
Engine misfire at a no load throttle and cruising. runs okay at acceleration, but has a loss of power different cylinder misfire every time i read engine code. new computer,new plug wires,new plugs,cap and rotor.
Aug 5, 2020 at 7:49 AM
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KASEKENNY
  • ✓Experienced Mechanic
  • 18,907 POSTS
We need to do a couple things. First and foremost is a compression test. Here is a guide on how to do that. Let me know what the PSI is for each cylinder.

https://www.2carpros.com/articles/how-to-test-engine-compression

Next we will need to check for a valve issue. Do you have a vacuum gauge to check the intake valves?

For the exhaust valves we need to do the dollar bill trick. This means you hold a dollar bill over the tail pipe with the engine running while it is misfiring and see if it feels like it is being pulled in.

The next thing is to check for a vacuum leak. Here is a guide on how to do that:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know about all this and we can go from there. Thanks
Aug 5, 2020 at 11:08 AM
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CHARLES STEELE
  • MEMBER
  • 37 POSTS
it will be a day or so before i can get it in my shop. working on backhoe right now.
Aug 5, 2020 at 4:03 PM
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KASEKENNY
  • ✓Experienced Mechanic
  • 18,907 POSTS
Totally understand. We will be here when you get to it. Let us know how you make out. Thanks
Aug 6, 2020 at 10:56 AM
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