Hey Rob,
       I had a similar problem a few years ago, mine died off sometimes when
I let off the gas and coasted.  Flip the key, and it came right back on.  It
ended up being a problem in the ECU.  Turning the key off reset some
transistor or something, temporarily fixing the problem.  I lucked out and
found one in a yard for $70, and it fixed the problem for good.  Nothing like
getting a brain transplant!

Of course, clean all electrical connections first, including the ground
straps on the engine and tranny.

Bill Marshall
85 GL Tiico
PHX AZ