I bought a 2004 F350 not running due to the oil cooler ruptured and caused oil temp to melt the stand pipe which in turn caused the IPR to get clogged up with small particles of plastic. Anyways I replaced all that and it busted right off but I believe I am having a issue with the FICM or injector harness?? Sometimes it will idle smooth as can be and sometimes its rough idle and I can mess with the connectors on the FICM and it will smooth out. I dont know if its the actual harness or the FICM causing that?? I put my scanner on it and when it is running at idle it has like 24-28 volts and when giving it throttle it has dropped as low as 17 volts. Should I replace the injector harness and see what happens or does it need a FICM reguardless?? Thanks