Truck won't start NEED HELP
 

My brother has a 1998 truck. He has been experiencing hard starting after sitting for awhile. He tried to start it last night but the batteries were dead, so he bought new ones. Now it turns over rapidly and is blowing black smoke. I finally started for about 10 seconds. Where is his fuel pumps. He has dual tanks.

What could be wrong. Before it would finally start after a while, then be fine for a while

This will sound dumb but check the oil. The Powerstroke uses high pressure oil to injest the fuel, if its low on oil they run like crap and wont start.

if its spitting black smoke its getting fuel. sounds like an obs. its mounted in the valley of the engine.

check the glow plug relay. jump it and see if it starts