Ya know, I had a crank, no start issue with my 2003, it was a damn fuse in the interior fuse panel. A little red one between to relays about the middle, kinda by itself. I have no idea how it popped, but after trying MANY things that didn't work, that fuse was the issue.

 

I will look for that in the morning. Doesn't make any sense but I'm running out of things to check! I'm crossing my fingers!

 

Does your truck by chance have the butterfly valve in/under the intake elbow, check to make sure it's not closed, this has happened quite a few times. I don't think 03's had it, but we've learned around here to ask, we've seen it on trucks that should not have had it.

 

Ok, checked that fuse and checked for the butterfly valve and there is not one on this truck. Had a local tech tell us they have seen several 6.0's with seemingly correct ICP readings (1500psi) but failed HPOP. This doesn't make much sense to me, has anybody else seen this?

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he also said said a good way to verify this is give a quick shot of starting fluid and if it runs on that, it's the HPOP? Tried that and with a really quick shot of starting fluid and it just seemed to slow the cranking speed.

 

if you ever use starting fluid/which you shouldn't/ turn the key on for 2 minutes to make sure the glw plugs turn off because it can blow your intake off if the glowplugs are lit . If you have the ICP reading that you show thenthe truck should start if it is getting fuel and air providing the FICM is telling the injectors to fire.
We know a stuck turbo can cause a no start, did you remove the airfilter assembly and spin the turbo?

 

Turbo spins good. When we shot it with ether it just started to turn over slower. I'm stumped!

 

Ether will make it turn over slower, stop spraying it with ether, you're going to do serious engine damage.

Ok, if the turbo spins freely and you have no boost, there is a major disconnect between the heads and the turbo, the exhaust manifolds come off the head, feed the up-pipes, to the y-pipe to the turbo, something in between is most likely blown.

 

We only gave an ultra fast spritz of ether. Don't worry, I know that can be catastrophic. Should there be enough exhaust pressure while just cranking to spin the turbo a little bit? Because it doesn't move while cranking. I just turned the impeller with my fingers to check it.

 

I don't think you'll see it spin until it fires. Does it spin free and easy? If the engine is cranking slower, it got more than a small dose of ether.

 

got it fixed!!!!!!!!!!! Took the belt off and fired instantly! Seized a/c compressor. Cranking RPM was above the "required" speed but apparently not enough.

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Thanks to everybody for your help and input. I really appreciate it.