[1Bubba]

03' F350 6.0... 90k miles.

Will start cold but sounds different than before. Drive away and it has no power, will pull all the gears but struggled to get up a steep hill near my house. Shut it off hot and it turns over but will not restart for 30 to 50 minutes. Running down the road, step on the pedal and it falls flat, let up and it surges for just a split second and then returns to no power.

History in no particular order... Fuel filters about 20k miles ago. EGR and Oil cooler done 1500 miles ago. FICM @ 37k miles, New injectors @ 1500 miles (the good ones). Air filter 500 miles ago. Oil change 3500 miles ago.

I do not have an OBDII reader so I don't know about any codes. No check engine lights have ever illuminated. Coolant level is steady w/ no additional oil in the water so I believe the EGR/ Oil Cooler deal is over.

Anyone seen this before??? I am at a loss, any help is appreciated.

Signed- Really frustrated in Texas
AKA Bubba

 

[Sic4fitty]

I'm no diesel tech but mine is an 06 and I believe you dont have a snap to connect fitting at the HPOP. Its probably the O-ring(s) on the oil ports under each valve cover.Whatever the technical term for those are??But there is a dummy plug and then a longer one in the back that will actually pull apart when you pull it out, make sure you get both pieces out! I had this same issue on mine with no warranty and did the STC fitting,and the O-ring job under the valve covers when the STC didn't fix the problem.I did these jobs myself using all the knowledgable techs on here. Your defintely at the right place to get help...But not from me, I just have had similar problems.:thumbsup:

 

[bismic]

It could be the ICP. One way to tell is to unplug it and see how it runs. the computer will estimate the ICP without the sensor input.

 

[w_huisman]

If the idle smoothes out when you unplug the ICP, it doesn't necessarily meant the ICP sensor is bad. I just went through a similar issue with my truck. The idle was rough. During diagnosis someone suggested I unplug the ICP sensor, and the idle immediately smoothed out (for about 5 minutes). I immediately thought it was ICP, but it turned out to be an injector. So I'm not sure exactly what unplugging the ICP actually proves.

If pulling the lid on the upper fuel filter and repriming seems to help, you're probably getting air into the fuel system through a failed injector seal. Pull the upper filter, disconnect the fuel pump, and have someone turn the truck over while you watch the bowl for bubbles. If you see any, I'd suggest doing the balloon test as described on the diesel doctors dts website to identify which injector seal is failing. If you have access to a scanner (sometimes parts stores will scan your truck for you or allow you to use their scanner), check for cylinder contribution faults and dtcs, as they can also point you towards the problem.

If you want to check the HPO system for leaks, pop the left valve cover off and use a rubber nipple on a shop airgun pressed into the allen screw hole on the HPO rail. Listen closely for an air leak. Also, with the scanner, check the duty cycle of the IPR valve. If it's closer to 85%, then you have a HPO leak. If it's 30% or less, your HPO system is probably OK.

PS- Change those fuel filters!

 

[bismic]

The ICP's were pretty common to fail on the 03's. IIRC, unplugging the ICP puts it in a mode where the computer estimates the ICP from other information. If the ICP is putting out a bad signal, removing it should result in smoothing it out well enough, and it should allow it to start (again - according to what I have read). I wonder why unplugging the ICP would smooth out an issue with a bad injector ??

BTW - w_huisman - great posts on the injectors and balloon tests!

 

[jimmy]

snap to connect fitting is a 2005-2007 feature. 2003-2004 have a different plumbing system for high pressure oil feed to injectors.
In addition to other things mentioned here, the high pressure oil pump failing will cause your symptoms. Makes just barely enough pressure to run when oil is cold but with warm oil the minimum oil pressure needed for PCM to operate injectors is not reached during cranking with starter.

 

[w_huisman]

snap to connect fitting is a 2005-2007 feature. 2003-2004 have a different plumbing system for high pressure oil feed to injectors.
In addition to other things mentioned here, the high pressure oil pump failing will cause your symptoms. Makes just barely enough pressure to run when oil is cold but with warm oil the minimum oil pressure needed for PCM to operate injectors is not reached during cranking with starter.

Just to finish this post off right....

Check the IPR duty cycle with a scanner. If it's high (close to 85%), then pressure test the system to find the leaks. The noise made while pressure testing the system will lead you to the HPOP if it is the problem.

First nail down which system (fuel, oil, or sensors), then nail down which part in that system.

 

[1Bubba]

Thanks to everyone for your replies... ICP had a little trash in it, replaced it and still no change. OBD2 says has about 800psi on the HPOP so we believe that is the culprit. Another $560 bucks and 4hrs shop time and all will be well... Except my wallet.

Man I love this truck!!! NOT! :O

 

[w_huisman]

800psi at idle, or during cracking?

I'm still curious about the IPR duty cycle (i.e. how far the valve has to open to maintain that pressure)...

I have my fingers' crossed for ya! :thumbsup:

 

[legion33]

just curious did your truck slowly lose power or all of a sudden. my 05 was losing power in and out after i changed #2,#8 injectors now it struggles to reach 30mph. it starts great idles rough revs up smooth but no power under load. should i have changed o rings on that oil tube under oil tray.