If I remember correctly, one way to diagnose a dying pump is to check current flow at the fuel pump relay socket: remove relay, bridge the pins for the pump, and read amps. I believe max allowable is somewhere around 6-8 amps, but it varies by model and year. Too much current draw will kill the relay, so more important is if the relay is busted (non-start or stalling), check current draw before installing new one.

fyi - all of our cars have the original fuel pumps in them (knock on wood).

-anthony