I have a 1967 Dodge Coronet R/T, 440 motor with a mild cam, 2 fours, 2-1/2 inch headers and 727 trans. The ignition system was changed to a Chrysler electronic system years ago. Several months ago, when I tried to start the motor, it would crank but not start. It was not getting fire to the plugs. When I turned the ignition switch completely off, the motor would ‘jump’ and act like it would backfire (it did a couple of times). Eventually it would start, after I pulled off and put back on the coil wire between the coil and distributor cap.
I have since changed the ignition switch, ballast resistor, and control module. But I still have the same problem except now it won’t start at all. What could be the problem and how do I solve this, short of putting on a $900 MSD, or the like, ignition system?

Thanks for your help.

I would check and make sure all your grounds are good. Also I think the box itself should ground to the firewall...

I'm no good at troubleshooting these things, but if the ECU, ballast, and coil are known to be good, what about a bad pickup coil in the distributor or perhaps the wrong gap between pickup coil and reluctor? IIRC, the gap should be .008" (with a brass feeler gauge), but others can chime in - my FSM's not handy right now.

I suspect pick up as well.

Mike

I am thinking it could be the pickup coil also but I wasn't sure if the whole distributor needs to be replaced. When it runs, it runs well. I will change the pickup coil and also check all of the grounds when I get back. (Having to work out of the area for now.)

Thanks for all of the info.

Also check the gap of the pickup in the distributor .

I just had the same issue yesterday with my 69 RR with electronic ignition. It was the coil.

take off the yellow "ign" wire from the starter relay to disable the starter. seperate the 2 wire dist pickup connector. Coil secondary wire (dist end) held 1/4" from a ground. Have a helper hold the ign key to start as you touch/break the male end of the eng harness half of the dist pickup connector to ground repeatedly like Morse Code & see if the coil wire sparks. If so all is good in the 'hood except for the dist pickup/reluctor/connector wiring. Everything can test good when cold then act up continuiously or intermittently when hot but this may help you get started.