2004  3500 injector line to corossover tube can you have air leak without fuel leak make for a hard start

sorry I am not %100 sure what you are saying,

 

Are you asking if you can have a air leak in your cross over lines that you cannot see and that can cause hard start issues?

I'm going to shoot from the hip.

I just got done working on a 2005 Cummins that was able to start easy but the truck would only travel a short distance and then rail pressure would fall out. That is a loose cross over tube.

Now a bad injectors(s) that are leaking excessively would most likely cause hard starting.

So for testing I would remove all the injector line and torque the cross over nuts to spec. Then test drive and see if it goes away. If not I would bench test all 6 injectors see where your at. If any are failing I would replace them as a set of 6. Too many time I see people cutting corners and replacing only the bad ones and end up doing it over and over till all 6 are replaced.

air leak  without fuel leak at conector line to crossover tube

Inside the head is possible. It would leak pressurized fuel out in the head and "may" draw in air as well. Check the back of the head for the return line to be leaking which might draw air in.

Hard starting can be because of lack of rail pressure or air leak issues. So to see rail pressure you going to need a live data tool like OBDLink LX dongle or similar to read the rail pressure while cranking.

thanks