car shuts off on start up

Is the security light on steady or flashing when your car starts and dies? If so then you have a theft system problem. You can have the security system scanned for fault codes which can help pinpoint the cause if that is your problem.

Mine did the same. It turned out to be a dirty throttle body. Had it cleaned at 80k miles hasn't stopped on me since and im up to 110k miles

try your purge valve located under hood by manifold