Hi went for a drive today for about a half an hour. i stopped and turned off truck for not longer than 5 mins. when i returned i was able to start engine, but it ran rough then cut out. i repeatedly tried to start it but nothing. it cranks but doesn't fully start. i banged on fuel tank, and same thing crank and sputter then die. any ideas. i was thinking fuel pump, but could vapor lock be the culprit. I have a 2001 ford ranger 4x4 5 speed with 145000 miles on her.