First off I'm new to the 6.0 world so please be gentle 😉, recently bought a 2004 F350 6.0 with 240k on the clock. I got a pretty good deal cause the truck had some issues. The truck will start and stall several times in the morning then start and run fine, and restart on the first crank that day, once it sits overnight same scenario again. So I did some research. The truck does have a cts edge tuner so I pulled up the icp and everything looked fine. Ficm voltage is fine at the ficm and on the edge. The only thing I noticed was the oil pressure gauge on the dash never moved until the truck started, upon research it's just an on off switch and has no bearing on the truck starting. It has the correct oil filter and cap (factory ford new). I have noticed that the filter housing is drained overnight and it has a new filter drain back valve. I don't think that has any bearing on my starting issue though because if so every 6.0 would do so when the oil was changed. A friend hooked up his snap on scanner and watched the ipr, it would start out shut when the truck would start and stall then cycle when he truck started up. He said the if the hpop fails it's usually when it's hot and has a hot start problem and not my scenario. He told me that sounds to him like the high pressure system is bleeding down overnight. Standpipes, plugs or hpop oring. He said I need to air test it. So I ripped the top end off of it, wanted to egr delete it anyways. So I have an air fitting in the ipr fitting, and put 150 psi to it, and I hear no air comming out anywhere. Not out of the valve covers nor is there any air bubbles in the oil resivour which was full of oil (I assume that's the resivour for the hpop under the oil cooler). I bench tested the ipr and it is working as it should. I'm at a loss, and I have a truck ripped apart in my garage. Anyone have any idea? What am I missing 🤔

 

I'm thinking vacuum leak, but hate to recommend you put it all back together and end up proving me wrong.

 

Believe you have a series of issues..........btw --- the reservoir will drain overnight, on the HPOP front ---smaller leaks are HARDER to locate.
Some questions:

(1) With key on did you get nice consistent clicks on the injectors?
(2) While cranking did you take note of any internal engine problems (compression)-- basically was the crank consistent with battery power applied?
(3) Did you run a cyl contribution / relative compression test -- this test is one of my favorites.
(4) Did you remove the driver's side valve cover during the air test?

 

Mods please move to the 6.0L forum, lots of expertise and help there.

 

1,2,4 yes
3 no
And not quite sure how to do so if I'm honest
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Ford dealer or someone with real IDS, AutoEngenuity won't run the uncompensated test.

240k on an (original?) HPOP? This is one of the very, very few situations where I might say swap the hard part out blind if you absolutely can't find someone with the computer and program to run the tests correctly. $520 for an Accurate Diesel hpop is not the most expensive part on the truck by a long shot, you can obviously do the work, and it's a solid probability you're doing the pump in the next 100k anyways.

 

Excellent advice from texastech_diesel. I'll add that AutoEngenuity is a PITA.

Aerial Tech --- (off topic) do your work on Altec's stuff? (I have a boom with some leaking hydraulics going up to the bucket from the joint -- tricky part is pulling the (orange) replacement hydraulic lines thru the boom).