'87 Fuel pump problem

Have a Throttle body fuel injection system on '87 V6 S-10. Quit running after about 5 minutes of acting like it was starving for fuel. It was running great before. Won't start at all now. Fuel pump runs when ignition switch is turned on, but fuel pump relay shuts it down after about 3 seconds. Does this each time key is turned on. Can hear the fuel returning to the tank for the few seconds the pump is running.
Need some ideas and steps to go from here to diagnose.

Thanks,
Joe in Boise

Assuming you have good oil pressure replace the oil pressure switch, i have the same s-10 with a 2.8 btw good luck on changing it, i love them G.M.engineers..

The pump shutdown is normal. It is intended to pressurize the system, then wait for an rpm signal to the ECM to turn it back on. Oil pressure will also turn it on, if necessary. I suspect that the pump is tired, but testing will reveal that. Ray