I remember somewhere that I read that the electric fuel pump will stop working under certain conditions to keep fuel from pumping (ie: a wreck, engine turns off, etc..). I do not know if there are sensors or switches (probably both) that will kill the electric to the pump under these certain conditions.
Now the question would be, what are these conditions and what controls the circuit? Seems youv'e checked the obvious and know what you are doing...you are probably close to solving the mystery.
SgtDel
aka "Andy"
www.delbridge.net
1979 Big 10 383 stroker
1991 Blu 'Burb 3/4 ton 4x4