2002 Chevy S-10 fuel delivery

I have have had problems with my 2002 s10 pickup fuel delivery. I would not start one day and the fuel pump would not run so I replaced the fuel pump. It ran fine for a few days then it died again and would not start. It was not showing any codes with the scan tool. I tried everything and got it started after unpluging the connector to the fuel pump (the one just outside the tank) and reconnecting it. The vehicle ran fine for a few days then it happened again, the only solution I could find was the same. This has happened a couple of times since with the same results and solution. Unhooking the battery did not work. Resetting codes did not work. The relay is fine (I swapped it with another). I don't think it's the oil pressure shutoff becuse the oil pressure is good and the fuel pump does not run when the ignition is first turned on. Any hints of a possible cause would be appreciated.