[Capri306]

Assuming that your ignition module is functioning and the fuel pump is good, if I were to take a stab in the dark, it'd be at the coolant temperature or mass air flow sensor(s).

You're going to need to do some more troubleshooting to nail this, though. "It just shuts off" or "doesn't start" isn't enough to really diagnose. You need to check and see whether you're not getting ignition (spark), fuel, or both, when it dies AND when it will not start. I'm not going to make any more bets until it's established whether it's an ignition- or air/fuel-related problem. There are simply too many variables.