01 F450 7.3 rough idle
01 7.3 with 342000 miles. Has a rough idle, worse when cold. Runs good off idle.
Already replaced HPOP, ICP, IPR, UCVG with injector harness, 8 Injectors, reworked heads w/cups, PCM, Glow Plugs, new oil change and fuel filter.
I haven't checked the fuel pressure or volume yet. The engine was started with the fuel filter cap off, by mistake, engine ran and accelerated but made a mess. I think that would rule out fuel delivery.
PCM was replaced because it was back feeding 10 volts to the IPR. I had voltage on both sides of the IPR connector
The #8 injector is in the #7 cylinder. I haven't had a chance to change it yet.
Can the #8 injector scenario cause the rough Idle? Is there a way to test the IDM? What am I missing?
All advice is welcome and appreciated.