Cm2250 Won't prime/no fuel in water separator

[HamblinTrucking]

(06-09-2021 )Rawze Wrote:  Maybe pressurize the fuel tanks to 10 psi (via the bleeder tubes) and let it sit for an hour... see if there are any fuel line leaks. CAUTION: whatever you do ... If you have pressurized the fuel tanks up to check for leaks ... NEVER try to open the fuel caps if the tanks are pressurized. It is usually enough force to break bones in your hand or severely injure someone as the cap jumps off.

Ok, pressurized tanks for a few hours and it never dropped but 2psi and there were zero leaks. I did a laundry list of testing. I tested the fuel pressures for the gear pump and basically had nothing. So, I replaced it. It drew fuel into the separator and everything seemed good....... until today. No fuel in the separator again. Great. It has zero codes, no trouble starting and seems to run ok (other than not building enough boost and lower power). I have checked just about everything. It doesn't seem to have any air in the system. I think my next step will be to block off the ports to the separator and pull a vacuum on it to see if air is getting in it somehow.

Rail pressure isn't dropping either, its perfect.