Q: Fuel pressure

Twice in the past month my van has died as though its out of gas which it was not. I replaced fuel pump relay and checked all fuses. I checked as many connections as I possibly could and found nothing obvious. After many turns of the key over the space of a few hours and still nothing after sitting for a couple more hours It started and ran fine with no problems for the next month and then it happened again- both times it was towed back. The second accurence was exactly the same as the first time except for 1 thing- besides not getting power to the fuel pump- this time after it being dead for the first 2 hours the check engine light would not come on when turning the key. Each of the 2 times this has happened it had finally started on its own as though it needed time to cool off or something. The most recent time yesterday july 16 I checked the power at the relay- one wire had a constant 12v with key removed, another wire had 12 v with key turned to On .

My car has 137000 miles.
My car has an automatic transmission.