1981 E-150 302, 2bbl, auto trans, all stock...

One day in July I was sitting at a stop light in traffic and the van dies like you shut the key off. Pushed it into a parking lot and began scratching my head. Turns over perfectly but wont fire, carb is full of fuel and at that point I assume something is dead in the ignition circuit. So I call for help and before I could be rescued I tried turning it over again and it fired right up instantly. Drove it home just fine and it didnt miss or stumble at all. My first guess was the ignition module was starting to die so I went and bought a new unit. The next day I'm pulling into a parking spot and it shuts off the same way. 10 minutes later it starts right up and I rush it home once again so it doesnt end up stranded in a bad spot. I cant remember the timeline exactly but at one point where I thought I had it fixed, I drove it somewhere that day and left to drive home at night... It started right up and when I turned on the headlights, the headlights and all of the dash/heater control lights were dimming and lighting back up eratically every few seconds. Not really in an even pattern like a turn signal flasher but just a few seconds here and a few seconds there each way. At that point I limped it home and it had me thinking that maybe the alternator was charging spurratically but when I got it home I shut the engine off and the lights were doing the same thing. Also having the ignition cylinder turned forward or having the key out didnt affect the light surging. I dont know for sure if these 2 problems are linked because it was probably 2 weeks or more that went by before I drove it at night since the ignition problem had started. One more thing about the ignition issue is that I have driven it places where it ran just fine and it was allowed to sit until everything was dead cold... then when I tried starting it wouldnt fire, then trying again later it would fire right up.

Things that I thought were suspect and have replaced new since it started having trouble:

Ignition module
Coil
Voltage regulator
Ignition switclh (not the cylinder but the electrical part)

No luck so far.
Any ideas?

 

Replace your batttery cables. It sounds to me like you have a bad ground. Either to the body or to the engine. Also I'd have the battery tested to make sure it's not developing a bad cell. When you buy the NEGATIVE cable make sure you get the one WITH THE 10 gauge PIGTAIL on it, as you will need to ground the core support for the voltage regulator to work. Replace ALL the cables, from the battery to the solenoid, from the solenoid to the starter and the ground. If that doesn't clear it up start checking fuses. In '81 it's going to have GLASS fuses so be careful removing them.