It sounds like heat soak to me. I have a 96 that I have wrapped the entire fuel rail and installed the heat shield on. and the last couple days it was into the 80's here so if i shut it off after driving for a while, it would spit an sputter, backfire, not rev up, and stall. it restarts and after some gentle massaging with the throttle pedal, will clear up and run like hell. I have poured a bottle of water over the fuel rail, which cooled it immediately and the problem was gone. I have done this when it was stubborn and wouldn't restart.