could be the fuel pressure regulator, seen them do the start then stall, then run, first thing in the morning.
could also be a real dirty throttle body, or fuel pump on its way out. do you hear the pump whine when the key is first turned? not cranked, just turn to run, listen for the whine, its the pump priming the lines. also check the fuel rail for pressure, theres a valve on the rail, uncap it, push the center of it, see if gas shoots out, watch your eyes, it will spray out all over. rag over the valve is a good idea.
