[apcnc]

Could be a broken wire from the switch in the steering column. Tilt wheel? Also check the ignition relay and wiring.

 

[apcnc]

That's pretty good compression for that that engine. You may trace the wire to the fuel pump as well. It may even me shorting or pinching the wire. Maybe something else shorting. Does it die immediately? Could be the alternator. May disconnect it at the alternator and drive it in the daytime and see if it happens? Make sure to disconnect the battery end or insulate it well.

 

[apcnc]

Did you ever check the coil wiring all the way back? And engine ground? Just really sounds like a broken wire or bad connection to me. The map could be acting up but idk if it would die that fast.