Engine backfire

1998 DODGE DURANGO
312,505 MILES • 5.2L • V8 • 4WD • AUTOMATIC
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DEMETRYM95
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  • 1 POST
I just changed out the spark plugs and wires today after I started to get a misfire code for cylinder seven a few days ago. I did it one at a time so then that way I do not mix up the firing order. I did have to remove the air cleaner box to have better access to the passenger side spark plugs and used WD40 on the spark plug on cylinder three. I did not move anything else around or take anything else out. After I finished I went to start it up and it would crank but would not turn over. I then went back and rechecked my work and realized that I ended up putting the wrong wires on the wrong plugs on the driver side; after I switched them to where they were to be it started right up, but now has a rough idle and backfire sound, the sound goes in threes 1) loud, 2) slightly low, and then 3) when it is almost faintly heard. What could I have done wrong, or what kind of suggestions would you have to help me fix this problem?
Jan 2, 2018 at 3:39 PM
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STEVE W.
  • CERTIFIED EXPERT
  • 15,113 POSTS
Double check your plug wiring again. A backfire like that is a spark on the wrong stroke. This is the firing order for the 5.2. Check out the diagrams (Below). Please let us know what happens.
Jan 2, 2018 at 5:46 PM
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KASEKENNY
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  • 18,907 POSTS
I agree with Steve, more then likely the wiring is still not correct.

However, if that does not solve the issue here are guides that will help with backfire issues.

https://youtu.be/HiI_eeFg-2A

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

Let us know what you find and we can go from there. Thanks
Dec 2, 2020 at 2:11 PM
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