[petek]

I'm going to guess that it's the ignition switch. I had the same sort of thing happen to me in a Porshe 914. All of a sudden and for no apparent reason the engine would die. Like RIGHT NOW die.

The second time it died I jiggled the ignition key and popped the clutch and the engine started right back up. Turned out that one of the main hot leads going to the ignition switch had broken out of it's crimp (why? I dunno). Soldered it back together, no more problem.