Billro, Im getting the feeling that the fuel pressure gauge you're using might be "out of whack" Just as mentioned before, if you are getting a return flow, from the FPR, you might indeed have enough pressure. Remember, you are looking for 80PSI BETWEEN the fuel delivery line and the fuel distributor body. During all these no start events, have you been checking for spark? Although spark might be present at all times, it could be WEAK, and breaking down under compression. Are the plugs wet and gassy smelling right after a no start episode? A new ignition coil could be the answer....
A good spark is whitish blue, not brownish orangy red..... Do yourself a favor, and try a another coil.
Dave......