So I just bought a 96 Ford ranger 4.0 did a motor swap got used 4.0 in it from the junkyard idles good can wrap it up in neutral or park it does backfire when letting off the gas. If I shift into any gear it tries to die acts like it's misfiring really bad does anyone have any suggestions

 

Welcome to the forum

Recheck your Coil Pack firing order
3 4
2 6
1 5
front

The 5 6 4 side always gets mixed up

So follow #5 wire all the way over to the center cylinder on the drivers side
Then #6 wire over to rear cylinder on driver side