6.4 misfire all cylinders bank 2

KHFord · July 11

08 f350, deleted, got towed in last night. Check engine light on with p0284 #8 low contribution. Monitor power balance and all cylinders on bank 2 are missing, injector kill on those cylinders make no change in rpm. Relative compression all 0%, no exhaust smoke, Injector electrical test passes, high pressure fuel test passes, no metal in fuel bowl, will not complete a KOER self test, wiggle test on harness makes no change. Any one run into this or have some thoughts? My 6.4 experience is very limited, could there be a fuel return issue? It seems electrical to me even though the buzz test passes. Thinking I will pull valve cover and test all injector circuits next but would like some other opinions.

mchan68 · July 12

Manual compression test.

KHFord · July 12

#2)380, #4)400, #6)400, #8)380. Valve cover is off, can hear the injectors all buzz on self test, injector resistances are within spec, all circuits between injectors and pcm are good, valve train is all good.

KHFord · July 12

Out of desperation I replaced #8 fuel injector since it is the cylinder that set the code and no surprise it did not fix anything. The line to the injector is getting fuel but i cracked the injector supply line with the engine running and there is barely a trickle of fuel leaking out. So the FRP sensor is on bank 1, which is working fine and that is why it passed the high pressure fuel test. I then cracked the line coming into the rail and had lots of fuel spray. I have removed the rail, no debris inside but the fuel feed port is plugged. It looks like there is an orifice in there that has shifted and is now blocking the passage.