6615 wiring or bad injection pump

Ok boys I need help. I’m bout at my breaking point with this tractor. 6615 had a bad miss at about 2k and leveled off after that. Replaced all cloth fuel lines, filters, new injectors, then at that came the big boy the injection pump. The pump fixed the missing problem. But about 2 days later after running like a new one it started to fall on its face. Eventually stopping completely and not starting back. Checked wires goin to the fuel shutoff solenoid. Wasn’t get volts. Jump a 12 color wire to it and it ran but really rough. So I thought well maybe it’s not getting enough voltage where I was robbing Peter to pay Paul. Long story short Replaced the hot wire, thought maybe it was broke somewhere. Started and ran bout 30 min-1hr backed up hay roll boom died. Checked wires again, had a broken ground wire, shoulda replaced it also, wel it was near the plug so just spliced it back there. Stared ran another 15 minutes maybe. Died again. Now I’m lost. Voltage to it now naught go up to 6 when cranking. My question is how many volts should it get while cranking? Or should I have it when key is on. I was told by dealer that it only gets it in waves and should be 12. All fuses are good, haven’t checked relays yet, I hear them clicking in but I know that means nothing. Ordered ignition switch thinking maybe that be it so who knows. Anyways if anyone has had this problem or how to chase this ghost away I would much appreciate it. My heads getting sore from beating it against the wall. O and the injection pump is still in time. I’m also leaning towards the reman injection pump could be faulty as well. But the voltage going to it is my concern.