Hey guys! Grab a cup of coffee... this is a long one.

I checked my ICP again while I was driving. I don't remember the actuals, but WOT i was right around 3,500 psi @ ~50 mph. When I shut it off and turn the key to the on position and monitor the ICP, it drops slowly... not an immediate drop to 0. That tells me that the HPO system doesn't have a gaping hole in it anywhere but it also means there about 100 other parts of this engine that could be at fault.

I did a diagnostic check again too. Now i have a MAP sensor out of range high, and another wiring related code. I'm going to pull 'er in the shop tonight and inspect all the wiring. I have the 6.0L coffee table book with the sensor curves, so I will check the sensor as well and post the results.

I'm also beginning to wonder about the logic board of the FICM. Even if the FICM is showing me 48V, that doesn't necessarily mean it's commanding the injectors properly, correct? I'm also kind of curious if the PCM could be erroneous. Sometimes my scanner says "The PCM of your vehicle is reporting that it does not support the following PIDs:
ICP
EOT
FL%
VBATT
VREF
VGT%
BOOST
APS%

Please check your PCM and retry."

If I cycle the key, everything works again. This is the one part im terrified to see the price of, since I can't get it at an International dealer... but with my luck, it will be the PCM.

Obviously I still have some work to do and I'll keep at it. Im determined to exhaust every other possible issue before investigating the PCM.

Since i'm still in the good graces of the shop foreman at the international dealer I used to wrench for, I had him and one of my buddies there come visit last week and look into what i've got going on. We found a pretty major problem, but none of us seem to think it's related. There seems to be a bad lifter and it's wiping out my camshaft. Nice huh?! The 6.0L deathgrip on my wallet continues... What do you guys think? Related or no? I know I need to work on that now, but I need to save enough money to do it. Thats a $1,700 job at least, doing the work myself and getting the parts cheap (and discounted ) from an international dealership! Oh well, what can you do?

To Be Continued...

Mike, Thanks for all your help!

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I finally remembered to get the official ICP psi written down while driving today. Based on that, I think I can rule out a faulty HPOP. 3,634 psi @ WOT. I'm thinkin' we're good there.

 

Yes that sounds right, I believe the 03's only go to 3600ish psi, so you're good there.

You might as well get an aftermarket cam, supposed to improve the drivability quite a bit. They're $600....

Sucks to hear that man. It's an issue for sure, but still trying to wrap my head around the truck just shutting off. If you're losing contact with the PCM that makes sense. Can you monitor FICM SYNC when it dies? See if it's losing sync. It should just be a "yes" or "no"

 

unfortunately i cant... yet. Im going to borrow my buddy and his OBDII tool this weekend, and do a full rundown.
After that, regardless of what we find, I'm going to send my FICM somewhere to get repaired. I re-soldered the capacitors once already, but my gun was too fat to do the little diodes or whatever they are. Any recommendations for where to send it?
I'm kicking around the idea of just replacing the logic board, since i can get it from international for like $175. As far as the FICM is concerned, i hate the damn thing an wish they'd have never conceived that idea.

Other than that, head studs are here, OEM head gaskets are here, the engine kit with all the rear cover seals and the like is here, the camshaft and all the lifters too. I really wish I had the money to do injectors while I'm in here. I know I'm gunna kick myself in the *** for not doing it while i have easy access, but what can you do?

I watched a couple vids on youtube of trucks with bad FICMs, and for the first couple startups it sounds identical. But once the thing pops off, it goes. It doesn't spit and sputter like the ones in the vid. But regardless, for the third time in a year I'm suspecting the FICM.

Its gunna be a fun couple weeks!

 

Don't worry about the injectors right now. They're expensive and it doesn't make sense to replace parts that are not bad. I think injectors are replaced too often on these when there are other issues causing them to not work right. Besides, they're not hard to swap around after you've got it all back together anyways. Valve covers are not too bad to get off to do it again if you need, don't sweat it.

FICMrepair.com who is/was a sponsor here has good rates.

 

Thought i'd give a quick update...

Good News:
Got new injectors (thanks lottery)
Sent in FICM for repair
Didn't Break anything

Bad News:
1 bad head (not suprised)
Busted Cam Follower
Destroyed camshaft


All in all, still doing good. Progress every day. I'll let you guys know if the original issue goes away when everything is all back together.

 

It's been quite a journey, but everything is back together. It runs and drives like brand new. The original issue remains. No codes. I'm going to have the PCM and FICM flashed to current level and we'll see if that takes care of it. I did some research on OASIS and found a troubleshooting chart for this issue, and im working my way down the list.

Any other ideas? I'm not ruling out an electrical problem, but if that was the case, why does it run and drive perfect?

I'm stumped...

 

My truck was doing something close, I put a fuel pressure guage on it and found I only had 40psi of fuel pres. replaced pump and now have 65psi. the bad news is the low fuel pres hammered my injectors, replaced 4 and now getting ready to replace the other 4.

 

I did finally get codes in the PCM. MAF sensor circuit intermittent, and ICP sensor circuit intermittent. Going to do some electrical diagnostics until I can get a fuel pressure tester. I think there may be a broken wire in the harness somewhere, but i'm going to clean all the contacts and try that first. If all else fails, I can pull out the harness and ohm everything out by the wiring schematics in the coffee table book and OASIS.

A fuel pump is not a big fuss is it? It's in the HFCM behind the filter right? It does sound kind of weak...

 

Replaced HFCM (aftermarket). No Cure. Fuel pressure is good, around 65 psi. Electronic?

 

It finally threw some codes...


I'm thinking wiring but not 100% sure... Ideas?