That's good info. Thanks.

The diagnostic path is always: Start with the most basic cause of the problem you're diagnosing, and move toward the most complex. Adding in, that nothing is assumed or over looked. If the plug wire set uses a carbon core coil wire, I would make or purchase a solid core wire. Carbon core coil wires are prone to failure, and they have a lot of resistance. Places like NAPA have bulk, solid core wire, and the ends, so you can make one inexpensively, and it'll last you decades.

If it were mine, I'd fire it up and give a little tug on the wires that are related to the Crane unit, the coil, and the distributor (the electrcal wiring, not "spark plug wires"). Sometime you'll create a stumble, or the car will actually die when doing that, and you have an ah-ha moment, because you find a loose connection, or maybe a wire that's broken inside it's jacketing. I would also start the car and wiggle the ignition key back and forth in the run position, in order to see if the contacts in the ignition switch electrical unit were failing and causing the issue. I'd also want to see how many keys were on the key ring, in terms of, does the owner drive around with 3lbs of janitor keys hanging from the ignition switch? Or is it just the actual car's keys and a house key(aka, no weighted load on the switch)?

If the quick wire tug test didn't produce a result, I'd loosen the fuel cap and go for a long drive. Or maybe remove the cap and squeeze a piece of foil around the filler neck, and slice a slot in it for venting, and keep the fuel cap with me, if I was worried that the fuel cap might fall off the car and be lost. I'd go 30min out and 30min back, with tools in the car, an see what happened. If it died, I'd jump out and test for spark and fuel, and see what I'd lost. If I could (sort of) remedy it there on the spot, I would. Otherwise, I'd wait that X number of minutes at which point it'll restart, and make a B-line for home. Then I'd fix it at home, knowing what I'd lost, and go out on another test drive to confirm that it was fixed.

__________________