Early '04 HPOP issues and no start..

[CJT2387]

A couple months ago My truck went into a no hot start issue, that rapidly progressed into no start at all. We found it to be an HPOP issue so I had the pump, IPR valve and ICP sensor changed and did head studs since I had wanted to do that anyway.

I was supposed to pick up the truck today, but it won't start and is still only building 270 PSI. While I was at the shop they plugged the tubes coming up through the heads eliminating the injectors from the equation and still only made about 270 PSI.

The shop is thinking the HPOP installed was possibly bad, but is still looking into it.

How often do the early model branch tubes fail? I heard they are a PITA to change and would require pulling the cab again as well as the transmission....

Anyone out there have a link to the early HPOP diagram so I can see how they access and replace the branch tube? I'm guessing this is going to cost me even more money I don't have yet.....

[CJT2387]

I forgot to ask:

Can a simple O-ring leak cause such low pressure when using a pump and IPR valve that is functioning properly?

[dhanna6powerstroke]

You don't have to pull cab and yes, one o-ring will cause a no start.

[CJT2387]

Well it is a little comforting that it could be just an O-ring. I guess I'll hope for the best.

[dhanna6powerstroke]

Originally Posted by CJT2387

Well it is a little comforting that it could be just an O-ring. I guess I'll hope for the best.

What does the PSI go to if you unplug the ICP sensor and will it start with the ICP sensor unplugged?

[mhatlen]

Originally Posted by CJT2387

A couple months ago My truck went into a no hot start issue, that rapidly progressed into no start at all. We found it to be an HPOP issue so I had the pump, IPR valve and ICP sensor changed and did head studs since I had wanted to do that anyway.

I was supposed to pick up the truck today, but it won't start and is still only building 270 PSI. While I was at the shop they plugged the tubes coming up through the heads eliminating the injectors from the equation and still only made about 270 PSI.

The shop is thinking the HPOP installed was possibly bad, but is still looking into it.

How often do the early model branch tubes fail? I heard they are a PITA to change and would require pulling the cab again as well as the transmission....

Anyone out there have a link to the early HPOP diagram so I can see how they access and replace the branch tube? I'm guessing this is going to cost me even more money I don't have yet.....

I'm not thinking the HPOP is bad, most likely a leak in the high pressure line.
Shame to have all that work done to see it still loosing oil somewhere.

[CJT2387]

270 PSI was all it would make, that was with the ICP unplugged.

[dhanna6powerstroke]

Command the IPR closed and supply compressed air through the ICP port while the oil cap and filter are removed. If you hear air, the pump is junk, if no air, pump is good and you have another issue.

[mhatlen]

^^^^What he said is where you go next, hope your ICP is on the valve cover and not under turbo