Start And Stall

OK out of the blue last night my g/f's FTO decides that when she goes to start it it's going to just stop. once it's been going it seems fine and it was running fine before hand...i have a few thoughts

1) crappy fuel (though she should have noticed before then or it should keep stuttering, also i filled my mr2 the same morning on the same pump, no problems)

2) it's fuel pump isn't coming on quick enough (but i doubt it)

3) The ECU start request which should give it extra fuel and give it a bit of a rev so to speak when she starts it is somehow not working, or it's cutting the fuel directly afterwards...

anyway i was wondering if you guys have any ideas on this, or if any of you have had anything similar?