I am having a similar problem w/ a '96 Isuzu Hombre. My truck will run but then quits. The relays in the glove box are getting overheating and failing is my guess but I don't know the underlying cause. I have replaced my fuel pump and those relays. When ever it dies on me and I attempt to start it right after wards I can't hear the fuel pump cycle. Is your problem like mine? What have you done?