Starts fine then just dies

Help Please: I was driving my van last weekend and it just died out, no warning sign what so ever. The van said “your not going anywhere today buddy”. It will start up again at any time, the problem is that it only stays on for 3-4 seconds. It does no difference if I step on the gas to try to keep it going, it’s like not registering that command. I replaced the fuel pump because a friend suguested that was the most likely culprit but problem is still the same (the gas filter was replaced in mid summer) .It’s not staying on long enough to register any trouble codes (I have an OBDII scanner).  I checked the fuse & most of the relays (main relay, EFI relay, fuel pump relay, function relay?). I have been Poking here & there after work and notice the Air filter some what dirty and replaced it. Now it starts and stays ON a few seconds longer starts to idle rough, bucks, hesitate and dies. About the 3rd attempt, I did revved it up upon start-up and it did hold high rpm but when I left go the gas it hesitated and died. It was late and cold and the battery lost it’s charge, so I went inside with my head down with still no clue.  Need some straight forward advice on this one. Thank you for your time