There have been instances when the fuel pump is failing but when it has been left for a time will restart the engine, check the fuel pressure from the test port, Schrader valve, on the top of the engine it should be 58 psi.
When my fuel pump failed the Schrader valve still had plenty of pressure. The car also restarted some hours after cutting out then wouldn't restart.
The 2 main clues are:
No sound from the pump on switching on the ignition - or it sounds different to normal
The spark plugs will be dry.
