Hey guys! I need some help. I have an 04 6.0. My truck was running perfect, no problems. I start my truck, it started idealing rough for a couple seconds then just died. After that it just kept cranking and no start. There are no codes, tried unplugging the ICP sensor and nothing. Checked the fuel filter and its filling up with fuel before cranking. Oil is at a good level. FICM is reading 46.5-47.5 before cranking. Checked the ICP Psi I'm only building 11psi and HPOP was replaced in October.

 

time for an air test and if no leaks (STC fitting upgraded, dummy plugs and stand pipe?) the HPOP has probably failed. Wouldn't be the first to have a failed HPOP, some fail even when new... read a post here, three in a row before a good one.

Pull the IPR valve and check the screen, that would be the first step for me.

 

Well at least the HPOP is under warranty but I'll still have to pay for labor which is bull***** because I just dropped over 4k in October on that and some other things. I'm gonna try the ipr valve next. If the screen is damaged is that a given that it's the ipr valve?

 

its a given that it may not be working correctly. IF the screen is damaged or plastic missing or the o-ring is damaged, replace it and try again. Those missing parts may be inside the HPOP... but try the IPR first. It doesn't run now, your not going to hurt it anymore by doing the IPR check/replace. Don't just go buy one either, check it first... and you need the special socket to get it off.

Did they upgrade the STC fitting, stand pipe and dummy plugs when you had the HPOP done? If the IPR is fine, then do an air test to confirm the HPOP, don't forget to command the IPR shut during the test so it doesn't give a false positive.

 

Okay I will try and get it off this weekend. I thought the 04 didn't have have STC fitting problem only 05-07? I'll check the paperwork to see if they replaced those. I'll update the thread if I find anything else. Thanks!

 

depends on the build dates, if it's a late 04, then you have a STC fittings.

 

My truck was built in 05/04

 

where is the ICP sensor located, on the passenger side valve cover?

 

Yes it is located on the passenger valve cover

 

then you have a late 04, has the STC fitting. Time for an air test.

 

Finally got the ipr valve off and there is no tears in it just a couple pieces of stuff. It's even been updated to the reinforced screen. Now what😕

 

Air test the high pressure oil system and listen for leaks. Bonus if you pull the valve covers because you can get a visual where the leak might be comin from. Pretty sure you don't have a stc fitting...those came on the 05's and up and easy to tell if you do or not by which cover you have on the oil pump. Oil pump not sticking threw the cover=no stc, pump sticking threw cover=stc. Sadly after that it could be the pump itself being a 04.

 

Sounds like a leak in high pressure system need 500psi to fire. Need tested

 

Well said - Only 05 and up w/ the troublesome STC fitting