2007 F450 6.0 Liter Hot Start Issue

Have a 2007 F450 at work with a B31 drill rig on the back of it. Truck has been having hard start when hot issues and eventually quit. Our guy replaced the fuel moduel which from my understanding is essentially like a lift pump of sorts. It is under the driver side seat inside of the frame rail. In any event that fixed the issue where the truck would not start at all. Now that that is fixed the long cranking when hot is still here. Truck has about 45,000 miles on it albeit some hard miles and heavily loaded. Any ideas for a 6.0 liter dummy to look at? I come from a 12v cummins so consider my lack of understanding of gizmos and gadgets lol. Thanks for whatever help one can provide.:Cheer:

Get a d@mn good scan tool and check all parameters while it's acting up. It could be as simple as the wrong oil filter and cap combo.

LReiff said:

Get a d@mn good scan tool and check all parameters while it's acting up. It could be as simple as the wrong oil filter and cap combo.

Click to expand...

From the standpoint of the filter and cap not sealing properly or is there a sensor of sorts which could be tripped by the wrong filter/cap combo? It is certainly possible the wrong parts were put on this truck given our guy's limited ability to work on the motor.

sounds like o rings on oil rail leaking by, that and the possible need for a regulated fuel return.. gets hot aerated fuel out of the head to help injectors out..

We had one that the stc fitting went bad and would only leak when hot.

Hot only restart - my list of suspects (in order)

STC Fitting at HPOP
HP oil rails at injectors (or case to head tubes)
Lube oil pump and front cover torn up (from STC snapring...)
Branch tube cracked

Thanks guys. I would assume these fittings are difficult to get to? Is there a good writeup or Haynes Manual which would help our guys get to replacing these parts?

Not the worst, not sure on a haynes book, I might be able to make a PDF from the international manual.


Basically the following has to come off

-Turbo (and associated plumbing)
-Intake (with EGR cooler)
-Turbo mounting bracket
-IPR Valve
-HPOP cover

At that point you're looking at the fitting, the updated part is once piece, no fitting, bolts to the branch tube and threads into the pump with an o-ring.

Will

If you're that deep in it, I would put a new oil cooler on it too. High EOT will degrade injector O-rings.

Rare for a later model HPOP to take a dump, but my buddy's 06 did. We did STC fittings, oil cooler, injector o-rings, etc. It got better, but the pump finally licked it

You need a scan tool to see what the high pressure oil is reaching. (P.S. I have a Snapon Modis for sale.......) IIRC its 500 psi for the computer to allow the injectors to be fired. If its low I start by pulling the driver side valve cover and removing the dummy plug and pressurizing the HPO system with with a air gun. Do that with the key on so the IPR is closed. I've had a couple trucks here recently that had blown Orings were the HPO rails go into the injector.

Sounds like we will need to get a scanner on it and go from there. We'll end up taking it to a dealer or my friend who works for a GM dealer (so he can scan it possibly).