N14 Tech problem

Need some ideas on a friends N14. Will run with a shot of ether, trouble starting hot or cold. Engine has new piston
liner packs and three new heads. Ran engine out of a bucket of fuel to omit the hoses and tanks- same problem.
This truck has been to four dealers including Cummins no success. List of parts changed related to fuel system.
Injectors, pump, solenoid, crank sensor, ecm. I'm leaning towards low voltage issues or grounds. Truck is a 96 IH.

Thanks for any ideas

Truck Shop

N14 Tech problem