06 6.0 won't start when hot

[LeeYates]

I'm new here and I feel certain this problem has been discussed many many times but I can't seem to find one that explains it. When i crank the truck in the morning, it cranks fine. After driving it and cutting it off, it won't crank after sitting for 20 minutes or so. If i leave it sitting for an hour or so, it cranks after trying twice normally. When i try to crank it after 20 minutes, it turns over but won't fire off. The oil pressure gauge registers nothing as it's turning over. This problem just started in the last few days and gave me the most trouble today. The fuel filter looks terrible but will be replaced tomorrow but as i have seen around the net, that probably isnt the problem. Any help would be appreciated!

[PHYRMN]

Sounds like a leaking STC fitting.

[PHYRMN]

Here's some good reading on your no start issue. Troubleshooting a No-Start condition

[LeeYates]

Thanks for the help. What is STC fitting?

[JasonY]

Snap to connect. It connects the high pressure oil pump to the oil rails/rest of system. Very common failure on these trucks.

Jason

[LeeYates]

How expensive/ difficult of a fix is it? I'm very mechanically inclined. I'm a motorcycle mechanic. Don't do much diesel work but I feel certain I could figure most things out

[PHYRMN]

Watch this and the part 2, it isn't a massively hard job, but do-able.

6.0 Liter Ford Powerstroke - High Pressure Oil Pump & Revised STC Fitting Part 1 - YouTube

6.0 Liter Ford Powerstroke - High Pressure Oil Pump & Revised STC Fitting Part 1 - YouTube

[LeeYates]

Ok. The problem progressively got worse. Thursday it started dying when it drops to an idle and will not crank back up for several hours. It has to sit about 2 hours before i will crank and even then, you may have to use a little starting fluid. I don't like to use starting fluid but it got me off the side of the road. But I took advice off of here and replaced to STC fitting yesterday. It is still doing the same thing. That affected nothing at all. Any suggestions?

[twoicebergs]

Firstly, let's clear up the terminology. You say if you crank it cold it starts and runs well, but when you shut it off it will not crank, as in will not turn over until it has sat for 20 minutes, correct? Then you say it will turn over (crank) but not start for about 1 hour.

If I have this correct you either have a weak starter, but more than likely you have something like a hydro-lock or a heat seizure event happening.

If it turns over but will not start when hot you have a HPO issue. After 20 minutes while cranking it attempts to run, but does not idle. After one hour it starts again, after cooling. This is classic HPO failure of either o-rings of the standpipes/dummy plugs or the HPOP. Once you read your ICP that will confirm. You need to air test your HPO system.

[LeeYates]

It will crank and run fine when its cold until it drops to an idle then it dies. It will sit there and turn over and turn over until the batteries are dead but it will not run. If you leave it sitting for an hour or more and come back, used to it would crank and run, now it will only crank with ether. If you let it sit over night, used to it would run, now it wont. It will only run when you crank it with ether. Not a starter issue. Like i said i just replaced the stc and that changed nothing. hope this clarifies some.