Here is something I would check because it happened to me, and a few other posters here on the board.

There is a ground tang, this handles the ground for the power stages,that power the spark plugs. What happened in my case was, while trying to get my hands to the bottom of the intake manifold to get to that large nut at the ball shape section, to make room for my big fat hands, I loosened a bolt that holds a plastic wire chase at the motor mount bracket. The 10mm bolt has a nut that holds the ground tang. Never saw it on dis-assembly so did not look for it on re-assembly. In my case the ground tang was just touching the metal engine mount bracket, so it started right up, let it idle for awhile and come to temp. Turned it off, went in to clean my hands and and it would not start back up. Took awhile to track it down, but it was not getting any spark. I did not get any codes for this one, either.

Hopefully it is as simple as this.

DanR '94 964 334,000 miles (100,000 on the new engine)
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DanR