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Discussion Starter · #1 ·
I have a 05 F250 that was recently purchased from auction. Unfortunately I don't know much about the history. It initially would fire up just fine when cool but would not restart after it had been running a while. I later loaned the truck to someone who made it about 60 miles before the truck died on them. They stated that they were driving down the interstate when they noticed what they described as a sudden loss of power. They said that it continued to run up until they took their foot off the throttle. At that point it died and has not restarted. We broght it back to our shop and have been messing with it since. We assumed that it was a high pressure oil issue but went ahead and checked the FICM which checked good. I had it hooked up to our OTC Genesys EVO and it showed that it was getting minimal oil pressure at cranking. I believe it was in the single digits or low two digits with the desired obviously much higher. This confirmed our assumption. My mechanic then suggested that we check the dummy plugs and stand pipe. He then returned and said that they had been replaced and that they were the newer style. Based off what he said you can visually tell the difference between old/new style. At this point we decided to replace the STC fitting. When we tore it all down we noticed that the STC fitting had already been done but seemed pretty loose. We replaced it anyways since we had already ordered one. We looked the HPOP over and assumed that it was good since it had a 2011 date stamped on it. Put it all back together again and still nothing. We then decided to go ahead and do the HPOP and replaced it with a known working pump. Still no luck. We are running out of options and at this point don't want to keep throwing time and parts at it. Any advice or suggestions? Also our OTC Genesys decided to take a crap on us so that is no longer a option...
 

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It looks to me like at this point you are following in the footsteps of someone who has already tried everything you are trying. Yes, you can visually tell the difference in the old style and new style standpipes by the way the seals look. It would be very rare for an '05 to have a bad HPOP, and if the STC fitting was already changed that should also not be the issue.

What were the results of the ICP vs. IPR readings? Have you tried unplugging the ICP?
 

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Discussion Starter · #3 ·
I am not able to check the ICP vs. IPR readings due to our scanner dieing on us and not having another available. I believe they tried starting it with the ICP unplugged but will have to double check. Any other advice? I also forgot to mention that they replaced the screen for the IPR but did not replace the IPR. The IPR housing looked pretty clean and shiney. I don't know if a clean one is a sign of one being replaced and a dirty grimey one being a sign of it being original. Don't know if that makes since...
 

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First, you need a way to read sensor data, otherwise with these engines you are taking shots in the dark. Troubleshooting by replacing parts gets expensive quickly.

If the issue is indeed HPO related there are still a couple of potential leak points. There are seals inside the top of the injectors which seal to the nipples on the oil rails. There are also the nipple cup seals on the oil rails.

It could also be a bad IPR or ICP. If it starts and runs with the ICP unplugged then its likely the ICP is bad. If not it could be the IPR, but the problem is there isn't a way to bench test it. You have to look at sensor data and eliminate everything else and then go on faith and replace it.
 

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Discussion Starter · #5 ·
On the seals around the injectors will I be able to visually verify that its leaking by cranking it with the valve cover off? For example will I see oil gushing past the seals or similar? I will check to see if they have tried cranking it with the ICP unplugged and what the results were. So if I am understanding this correctly the only remaining "common" issues would be the injector O rings, ICP or IPR? The ICP seems easy enough to test. I am sure I can pressure test the O rings with a air compressor. Will need to buy a adapter for that. Any suggestions on the best price for those? I can get a used IPR for not much so may just go ahead and try that as well.
 

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Buy a Motorcraft ICP as there have been lots of reports recently on here about Ebay or other cheap ICP's failing right out of the box or within a few months.
 

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The thing about air testing is that it only goes so far. Remember you need 500psi to command a start. Most shop air compressors are going to max out around 120-150psi. Things don't leak, or don't leak very bad at 100psi that leak a lot at 300psi, etc.

I can't say on the injector seals. I've never cranked a 6.0 with the valve covers off. I would think so though.

If you can get your hands on a known good used IPR that's a worthwhile test too.
 

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Pull and inspect the IPR as the next step. If possible, replace w/ a known good one if you do not see issues with the existing one.
 
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