05 F250 6.0 Will not start on HOT

[Roadking99]

Truck will fire up when cold but after I shut it off it will not refire! I have changed the IPR valve and that did not fix it! It runs fine, all oil pressures are up etc. Could it be a sensor???

[dhanna6powerstroke]

You have an HPO leak somewhere. I'm gonna say it's the STC fitting or dummy plugs.

[sinner6.0L]

you're better off just tearing it down and changing the STC and dummy plugs.

I would go after for the STC first

[Roadking99]

Thanks for the info....is there a PDF or engine layout somewhere so I can locate where the STC & dummy is located? I do know it was a bear to get to the IPR valve!!!

[dhanna6powerstroke]

Originally Posted by Roadking99

Thanks for the info....is there a PDF or engine layout somewhere so I can locate where the STC & dummy is located? I do know it was a bear to get to the IPR valve!!!

Turbo has to come out to get to it. The IPR screws into the HPOP cover. Try this link. http://www.forddoctorsdts.com/articl...icle-06-08.php

[HAM_RADIO_MAN]

Originally Posted by Roadking99

Thanks for the info....is there a PDF or engine layout somewhere so I can locate where the STC & dummy is located? I do know it was a bear to get to the IPR valve!!!

See the links in my signature for a lot of what you are asking for here is also a link to my STC fitting fix.


No longer a 6.0 virgin. New STC, Cleaned turbo, welded EGR cooler closed. PIC's

Q: What is a high pressure oil system leak.

A: On a 6.0 the fuel injectors are powered by high pressure oil in the range of 550 to 3500 psi. This oil is supplied by a high-pressure oil pump that is driven off the cam gear in the rear of the engine. The oil is transported via a network of connectors , tubes and passages that have o-rings , seals and connectors that over time will develop leaks. The main suspects are the stand pipes and dummy plugs under the valve covers inside the “ oil log” The next problem area on 05-07 trucks is what is know as an STC or Snap To Connect fitting. This fitting Blows apart randomly and your truck will be dead were it stops. This fitting is located on the output side of the HPOP and an updated solid part is available from Ford or International. High Pressure oil leaks can also occur at the injector o-rings or from cracked branch tubes but this is rare. The way to test for a high pressure oil leak is by injecting air into the ICP sensor port and listing for the leak. Some leakage at the HPOP shaft seal is normal. Normaly high pressure oil leaks will be characterized by high IPR values and below normal ICP values as well as hot start and rough hot idle problems.


Q: What is the best way to tell is my HPOP is going bad.

A: Remove the IPR valve and LOOK for Glitter on the screen. Any sign mean you need a HPOP as well as a new IPR valve.



Q: What are normal ICP and IPR values ?

A: Cold engine low idle ICP = 806psi IPR 29%
A: Cold engine high idle ICP= 960psi IPR 33%
A: Warm engine low idle ICP= 585psi IPR 24%
A: Warm engine high idle ICP= 735psi IPR 28%
A: If your engine requires a high IRP percentage to get the same or lower ICP you might have an internal high pressure oil leak .


Q: My engine starts fine when cold but, I shut it off to run in the gas station and now it won't start hot. When it cools off a few hours it starts right up.

A: You most likely have a high Pressure oil leak at the STC fitting, Stand pipes , Dummy Plugs or injector O-rings

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.The new STC fitting kit from Ford costs about $60 and has great instruction with it. You will also need to buy or make a 15/16 crows foot to properly toque the new fitting into the HPOP. The IPR needs a 1 3/8 wrench.