After the car cut off the last time for no apparent reason, I measured the voltage on the 6 pin CD box connector. At pin #15 the voltage measured 0.1v. I let the car sit for awhile and the voltage eventually jumped back up to 11.9/12v at pin 15.The car then started, then died after a few minutes with a reading of 0.1v at pin #15. Any ideas what the problem is?
I have replaced all of the fuel pump relays.
Rick '78 930

 

Possibly coil going bad. Check its resistence. if its not correct it will heat up and ruin your cd box quickly. (coils are cheap)

 

Coil and cd box were replaced. Pretty sure its a relay. Ever heard of the delayed action ignition cutoff relay?