1998 wrangler TJ 4.0: spit, sputter, backfire.

[aaron.0391]

1998 wrangler 4.0

Misses like crazy upon start up. Kinda levels out a little bit while idling. Rev it up around 2k or so and it back fires and pops like crazy.
New distributor & cap/rotor. New wires. Plugs are gapped. Fuel is at 49psi and holds. I have spark from the coil.
I read that on of the wires running to the coil is suppose to be a 12v constant. When I turn the key in, test light kicks on but then something clicks and it shuts off.
I swapped the asd relay with the horn relay and it's the same issue.

Kinda reaching out to people that are way more knowledgeable with this shit than I am before I take it in.

 

[hear]

Has it ever run right since the new distributor went in? If no, then I'm guessing you were off a tooth when you put the new dizzy in. I believe the timing is advanced pretty far at startup, and then drops at idle once it warms up. Then under load the timing advances again. It sounds like position of the distributor is one tooth too far forward, which is making the timing too far advanced under load, but just enough to be ok at idle.

 

[Jerry Bransford]

X2, backfiring is a good indicator the distributor's timing is off.