This is a good one 6.0l no start.
 

Okay back again and have done a lot of work since last post but still won't start. So far this is what has been done:
New stand pipe and dummy plugs
STC fitting
New Cam and Crank sensor
New HPOP
New Low pressure oil pump
New (8) fuel injector
New ICP and IPR
New FICM
New Batteries
New Starter
Oil pressure system checks good with shop air
Fuels pressures verified 62 PSI (blue spring upgrade) verified fuel flow at filer housing, lines and rails.
6.4L banjo for fuel rails
Good ICP pressure will get to 1100+ PSI
Good IPRv and IPR% KOEO and during cranking
Good FICM VP, MP 12/12/49
Good SYNC during cranking
I'm in the Military so I will leave for a while and come back and when i get time I work on the truck. I took it to a local 6.0L specialist in Jacksonville NC Tripple C diesel for diagnosis, then heard some pretty depressing things about their shop. All kind of businesses trying to get over on Military folks.
They couldn't figure out what was wrong. They said they fired it up and it would shut off at exactly 998 RPM but if they kept it above that it would run pretty good. it had no injector buzz when I took it to them KOEO so that lead to the injector replacement (that was their only recommendation). BUZZ came back after. I originally took it to them because I definitely feel it is an electrical issue and didn't have anything besides a SGII to diagnose it. They did also note something interesting as I did though........the ICP volts are at 4.0v+ and should be .08-.28v KOEO. they said that was fine HMMMMM.
Like I said this is a good one, the ICP volts could be due to a miss-wired pig tail replacement so I think I need to figure that out. (would that cause a no start? still doesn't start unplugged)
Its like there is no fuel getting to the injectors, no smoke, no attempt to kick on. So that is why I think electrical. This is aggravating really.
I can't think of anything else so hopefully you guys can assist.

HELP!!!!!!!!

Sounds like you threw everything but the kitchen sink at it. With all that work it will be almost impossible to figure out without getting all the vitals of the truck.

Sounds like it doesn't it, but every code has been eliminated. the truck has 171K miles on it. Ran great before the no start. SGII was the best investment but still ran into a wall. Besides APR studs I'm trying to bullet proof this truck.

Have you tested the low oil pressure yet?

You listed FICM voltage at 12/12/48.

Was that low side and high side at koeo or cranking?

Yes oil Low oil pressure is good. new LPOP

What year is it?
Unplug the ebp and see what happens.
Check fuse f2 22
Unplug vdf and see what happens.

That is KOEO, lowest volt for FICM VP and LP 11.5 and and the other starts at 49V and during cranking goes to 48.5 but after gets right back to 48 volts. From what I know of FICM all those volts are Great.

FICM volts
 

That is KOEO, lowest volt for FICM VP and LP 11.5 and and the other starts at 49V and during cranking goes to 48.5 but after gets right back to 49 volts. From what I know of FICM all those volts are Great.

It is a 2006 with 171K miles on it

Where is F2 22 fuse?

In slot 22 of the cjb

Fuses are good in cjb
 

All fuses in the CJB are good including 22, checked with a fuse check light. I also checked all the fuses in the engine bay and they were all good. I also replaced the relays for the FICM (engine bay) and the PCM (in the cjb)

Did you try starting w/ the ICP unplugged? Vloney posted up a situation a little while ago where he had a truck that wouldn't start w/ the ICP plugged in and the issue was actually a bad injector coil. Granted there were codes that might have given a vague clue, but I didn't see where you checked for codes w/ something other than the scangauge (and I wouldn't really rely on it for code reading).

Also, a FICM can read good voltage and still be bad. Only sure way to eliminate it (IMO) is swap out w/ a known good one.

ICP unpluged
 

I hear you on the FICM, I replaced it once and have had it rebuilt twice already. Each time same story good volts. The guys I have rebuild it (automotive scientific) told me there was nothing wrong with it the last time. I have tried with the icp unplugged and plugged in. I get the p2285 with it unplugged but no ICP code when it is plugged in, the volts just read 4v+. I didn't have any injector codes, i replaced the injectors becuase they ALL failed the BUZZ test with a Snap On diagnosis too. When commanded to buzz we heard maybe 1 click. After replacing all injectors BUZZ is back. (Spool valves were most likely stuck on the old injectors)

I understand you changed the ipr. But with the amount work done maybe check the ipr screen again. Easy to send junk through it after any work done to the hpo system.