RE: Engine Cutting Out
Mike, your description comes very very close to describing "Vanagon
Syndrome" or as VW described it in their service bulletin "Intermittent
Driveability Issues".  That or a bad/intermittent electrical connection.
Next time this happens try pulling over, shutting the engine off and then
back on again.  With Vanagon Syndrome this resets the ECU and things should
then be normal for from five seconds to five years, that's why it's called
intermittent.  And yes, I've BTDT, both in an '85 (stock 1.9L) and my '90
(stock 21.L)