My sons pickup is a 3500 5.9 2003. The engine cut off while driving down the road like you had cut the key off. If you turn the key off and back on it will start but only run for 30 seconds or 1 minute. When it goes dead if you try to crank it without turning the key off and back on before you crank on it, it will crank over but won't hit at all. He put a new lift pump on but got the same results. If you let it set all night and cool completely off it will sometimes crank and start and run for 10 minutes or so before cutting off. The engine has under 200,000 miles on it. Any suggestions on what might be wrong?

 

Is your ignition key black or gray? Any codes setting?

 

Sorry it is a 2002 model and it has a black key.