CM870 misfire under load

[Blackout26]

It does have the faults for the egr valve being unplugged. I replaced the fuel shut off solenoid, however I did not change the guts out or remove the guts upon reinstall. I inspected the guts and couldn't find any issue that stood out. I do not have a Davco unit. However I have not had to add any coolant since purchasing the truck. I will eyeball the bottom of the tanks in the morning prior to starting and see if i can see coolant puddles in the botttom. I will remove the guts tomorrow and see if the engine acts as you describe. I also purchased the metal gaskets as I am feeling confident enough to take them apart and reassemble them. I also have the compucheck and plate tool to test the injectors hopefully arriving tomorrow. Another note, if i start the engine it will idle smooth till the electric lift pump shuts off, then the stumbling begins again.

Thank you