1989 740 Turbo with automatic, air and 101K miles. This car runs great....when it runs. It will die for no apparent reason. And....it will not start at times for no apparent reason. When it dies, it's an instant death. It doesn't sputter or spit. It's as if I turned the key off. I let it sit for a few minutes and she'll start up. There were a few times when it didn't start. As if it had no spark. I come back, after saying a few choice words, and it starts up. Could this be a bad ignition module? Fuel pump? Distributor pick up?

I changed the coil and fuel filter. The problem still exists.

Any help would be appreciated.