MJ Still won't start

MJ 4 banger. Worked fine one day, next day it would not start. No, spark. Fuel pump comes on and it cranks fine. I replaced Ignition module and CPS. Coil checks out ok. If I stick A screwdriver in the coil wire and touch it to ground when starting I don't get anything until I stop cranking, then I get a short spark. Would this be an ignition switch or something else?
Dustin

Alright, I took off the invisible posting device. SO now somebody should see the post.

Nothing until you STOP cranking?

You didn't say what year MJ, but I don't have MJ wiring diagrams anyway. Here's a SWAG (Scientific Wild A$$ Guess) for you:

You know that the starting circuit bypasses the fuel pump ballast resistor, right? I don't know if this applies to the XJs and MJs, but back in the 60s and 70s Chrysler also used a ballast resistor (and AMC used a fusible link wire) in the coil circuit, to limit coil input voltage to about 9 volts when running. The starter circuit bypassed that and sent a full 12 volts to the coil so you'd have a hotter spark for starting.

If you have a wiring diagram, check the coil circuit to see if there's a bypass circuit that only feeds during starting. If so, it sounds like that's being interrupted somehow.

Told ya it was a guess

Thanks, I haven't had a chance to dig out the fsm. I am thinking that you are correct though. It seems like it has to be in an ignition power wire somewhere. I checked all of the fusible links, but need to check them again. Nect is to get under the dash and check out the ignition switch.
Thanks,
Dustin

I have replaced the ignition module, coil, ignition switch. Still won't start. If I turn the ignition on and pull of the one wire connector from the module and wiggle it around, I get spark at the coil wire. I though maybe it was loose, but it is doing this because the wire is disconnecting and reconnecting. So, I should be getting spark, but when I turn the motor over, I get nothing. Next to replace is the ECM, any ideas.

In an effort to help someone else out, it was the computer. I am kicking myself because it was my first thought, but I did not have time to go scrounge at the junkyard. But now the mj should be happy for a while with all of the new parts.
Dustin