Bad spark?

The starter sounds like it's cranking fine. I'm not familiar with those distributors at all. What is in it for a pickup? Does it have a magnetic pickup like a Mopar breakerless dist? Can you adjust the gap in the pickup/ reluctor?

Take the cap off and see if it appears to be a bent shaft. Wiggle the shaft sideways and judge how much slop is in the bushings, or better yet, remove the dist. from the engine so you can get a real feel for what's going on.

My guess is this is a distributor/ pickup problem.

Judging form the spark WHEN IT WORKS, I'd guess not a voltage problem, not a coil problem. COULD be something in the electronics package, but I'd suspect the dist/ pickup area first.

I'm not tryin' to chastise you, but this is one reason I don't like to run non--OEM parts. In order to "be safe" in case of trouble, you just about have to have a complete identical MSD system on hand when things go south.