96 Regal Intermittent starting problem

Hi, letely I've been having a problem with my 96 Regal custom 3.1L where every now and again it refueses to start, but i can try again a few hours later and it will start fine. When it refueses to start, i can hear a low humming noise and I can hear a relay clicking which i assume is the fuel pump. The humming noise sort of sounds like the fuel pump, only like it's jammed or something. I've tried replacing the relay for the pump with no luck. Anyone have any ideas? I'm thinking about trying to replace the fuel pump, but it's a lot of hassle, and I'd like to hear what you guys have to say before i do anything. Thanks.

There should be a Schrader valve port located on the rear fuel injector rail, passenger side where you can test fuel pressure. That is the best way to determine if the fuel pump is bad.

Ok, next time it heppens i'll give that a try. Thanks. :)