Ok, first off, I sincerely want to apologize: I have a full-size Ford with a 351M, but it's a '77 Thunderbird, not a Bronco. Problem is, the T-bird forums for that age car are almost 100% dead. Not many answers to be had from them. The full size Bronco crowd has probably more 351M's than any other group, so I'm hoping that you guys can help me out.
This is my problem:
There is an intermittent fault in my ignition system. It seems to shop up after 20 minutes or so of driving. I can always start the car in the morning, but 20 minutes into the 35 minute drive to work, BAM - it's done. When I try to start it again, there is no spark. Well, more precisely, there is no spark while cranking
, but as soon as the ignition is released to the "run" position, there is one spark ... but not, of course, enough to start the engine.
I've already replaced coil, ignition module (expensive red grommet, of course, not the cheap blue one! why is it that always happens?), cap, rotor, wires, and plugs. Only thing that I haven't done is replace internal components in the distributor. I'm getting power to both the ignition control module and the coil, even during the no-spark times. I'm pretty sure that the reluctor and the pickup coil are both good - the other day, when this happened, I could turn the rotor just barely a hair, but it was enough - the reluctor got close enough to the pickup coil and I could hear it click.
I'm completely at a loss as to what the problem with this is!
Any suggestions that y'all could offer would be greatly appreciated!!!