hard starting bravada

my friend has a 93 bravada with the vortec motor and it usually doesnt start but when it does it sometimes stalls. i am thinkin about gettin the bravada from him but i dont know whats wrong with it and dont know if its worth it. we tried the map sensor, and that didnt work. any suggestions would be helpful. thanks, ryan

Check it for trouble codes.

ill do that when i get the chance and ill keep ya updated