6.0 2004 early build. Will start in spurts about 3 times (the odd time it will crank and not start) then stay running all day and start like a top when it's just been running. It is a low HPO when sitting for a while issue. It only gets to 200-300psi for a bit until it starts.. Seems like the HPO is running back when its been sitting overnight. Perfect hot starts.. New ICP & IPR & Injectors. That didn't help that problem. The early 6.0 didn't have the valve in the standpipe, is that correct? What can do this?

 

Bad HPOP with early builds... go right after it.

 

Is it common for them to fail cold like that and work well hot?

 

Input shaft seal leaks so it reprise after it sits for a while.

 

But doesn't a seal leak make it hard for hot starts?

 

What happens is when the shaft seal leaks in the HPOP it allows the HPOP reservoir to drain causing long crank cold starts. Try parking the truck nose down over night and see if it starts better the next morning.

 

Ok thanks. I'll try that. I want to make sure that is the issue before i replace a $1000 pump.

 

LPOP system drainback? wrong oil filter?

 

The pump shaft seal is not sealing on the high pressure side.

 

Had the truck parking all pretty nose down. Started like a top this morning. Is it for sure the hpop or is there anything else I need to double check first?

 

Park nose up and see if it starts like crap, you could part nose down all the time until the seal completely fails.


Its the HPOP....