duramax runs sometimes

[seriousdiesel]

I have a 2001 Chevy Duramax at my shop. Initially It came in with no rail pressure. I installed a new modded pump from II, and a new rail psi sensor. Truck now has rail pressure, rpms show up on the scan tool, good lift pump pressure from the lift pump. Occasionally the truck will start and run, and when it does it runs fine, idles fine, everything is normal. Problem is, it wont always run, and when it wont all still looks ok- rail psi is fine, rpm shows up on the scan tool, but it just cranks. I have checked the security in the ecm, did a relink with the body control module via efi live, and swapped out the fuel injector control module with a module off a running truck, and still no luck. The only thing I have are a few codes.



P0380 "Glow Plug Feedback Circuit A" EPA
P0540 "Intake Air Heater Circuit" EPA
U1800 "Lost Communications With Fuel Injector Control Module
U2104 "CAN Bus Reset Counter Overrun"

I have visually checked wires, pins and plugs, cleaned and put on dieelectric grease. Im out of ideas. Anyone have this problem before? any ideas? Thanks in advance, Nathan

 

[THEFERMANATOR]

Have you checked teh wiring harness behind the alternator yet? I know some had issues with rubbing through at that point. Also check your wiring harness at the TCM over by the intercooler and power steering lines. This is another known chafing point. Your last 2 codes both deal with problems over the CAN bus for the ECM, TCM, FICM communications, so it sounds liek either a module is shorting out, or you have a wiring problem.