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5.9 swap issues

dw0783

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So I finished the 5.9 swap in my 2000 and I’m having an issue. Engine runs great in park or neutral. As soon as I put it in gear and give it any gas it starts popping like crazy out the exhaust like a backfire. No codes, o2 sensors were replaced when swap was done, new fuel pump, new plugs wires cap and rotor.

Any ideas?
 

pc1p

I do all my own stunts
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Some things to check that comes to mind...

1) Did you remove/rotate the distributor at all? If so, fuel sync can be off...
2) Did you swap spark plug wires? If so, did you confirm firing order?
3) Did you swap manual to auto? If so, the PNP indicator to the ECM wire may be causing you an issue. You can start the rig, then unplug the PNP switch connector at the trans and see if it does the same thing. If it doesn't, I suspect the PNP indicator wire to the ECM is not in the correct pin position.
 
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dw0783

dw0783

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I figured it out…it was the plug wires on the distributor due to all the crappy diagrams out there telling firing order.. completely my fault 🤦🏼‍♂️
 
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Wildman

Over Analyzer Extraordinaire...............
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Here are a couple of TSB's about the magnum engine.
 

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  • Spark Plug TSB.pdf
    216.7 KB · Views: 18
  • Spark Knock TSB.pdf
    206.8 KB · Views: 17
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dw0783

dw0783

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This got me straightened out. None of the pictures showing which spot on the cap really worked in my situation. This one did with the screw holes for alignment.

A684F49A-3616-4D34-983C-34BEFFB016F2.png
 
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