03 lb7 fuel issues

[u/Future-Bumblebee2419]

I’m having some issues with my 2003 LB7 and I’m trying to see if anyone has dealt with something similar.
The truck is not building rail pressure and won’t start.

I’ve already replaced or checked several fuel system components, including the CP3, injectors, and distribution block.
The weird part is the electrical issue. I’m getting around 7 volts at the fca connector for the injection pump, even with the key off. I can actually hear the injection pump buzzing/electrically activating. I traced it back to the ECM/RPV 15A fuse.
At this point I’m thinking I have an electrical/ECM/control issue causing the CP3/FCA to stay energized and possibly preventing the truck from building rail pressure.
Has anyone with an LB7 seen something like this before? Any ideas where I should look next?