On my way home with my 740 on the tow truck.

[Kirby J]

I want to second the first responder: this sounds like a crank sensor .
When mine went out, it was raining. After a few minutes the heat from the engine seemed to dry the line out, and it would
start. Sometimes it would run, sometimes it would only idle, and die as soon as you use the gas pedal. Aggravating!
If you drive these cars, this part will eventually go out. It pays to carry a spare.
It is an easy fix, requires you to remove one bolt on the back or the motor. I think it uses an 8mm socket. a 12 inch extension with u-joint helps. 10 minutes in the dark to replace. Quicker than checking a spark plug.
Kirby J