Why won't my Lull 944E-42 start after replacing the fuel filter?

[Devlh Laveighn]

My Lull 944E-42 with a Cummins diesel engine started sputtering and stalling before it stopped starting altogether. I cleaned the fuel system and replaced the fuel filter, but it still won't start unless using ether. What could be causing the problem?

 

[Fairy]

Seems to be a problem with the fuel supply, air bubbles in the fuel line, low fuel pressure, or maybe faulty injection pump. But since the engine starts with ether, I will suggest checking the fuel pressure, bleeding of the fuel system, and checking the condition of the fuel injectors.