I don't think the 4bt cummins has glow plugs, the 6bt in the dodge trucks have a intake air heater. There are a few case guys around so hope you get your answer.
Does it smoke while its cranking b4 it starts? That indicates fuel is getting into the cylinders. Sometimes a leak in the fuel system will allow air into the fuel line and the engine will have to crank up its fuel b4 it will start. It should puff smoke while cranking it.
If you think this could be the problem while the engine is running remove the return fuel line fron the injectors to the fuel tank and submerse the end of it in a bucket of fuel, if there is any air coming out the return fuel line (along with the returning fuel) while the engine is running its a sure sign of a leak on the suction side of the fuel system. Even a vary tiny leak can cause a hard start condition on a diesel engine.
I'm going to move this thread to the Case section of the Forum
Ken