so I got the new icp in tonight and still same thing with icp unplugged i get it to want to fire and sometimes fire but plugged in nothing. I am almost positive it is hpop with everything else being changed. On the troubleshooting link with icp unplugged it says ipr or hpop ipr is new so only leaves hpop. Can the hpop still filling up not necessarily mean it' not bad?

 

Is your block heater even working? Also to lasy to read the entire thread but have you done the injector o rings?

 

yes block heater is working and injector o rngs are new injectors where redone this year.

 

I think you need to build an HPO test gauge and put it on the rails so we know what is really going on.

 

that or a scanner but both of which are hard to come across right now being holidays and such. If I have the icp plugged in when the dummy oil gauge hits center as if I have oil pressure I don't get anything. No smoke no fire nothing. But if I unplug the icp and crank and the oil gauge hits that same spot on the dummy gauge I get a faster crank smoke and it either wants to fire or sometimes will fire. According to the troubleshooting guide if it does that with the icp unplugged it comes back as the ipr or hpop and the ipr is new. Granted guessing a little bit with no other option at the moment and the word of a different mechanic that is what he is saying it is

 

Correct me if I am wrong , but the dash oil gauge has nothing to do with high pressure oil. The only way to know what the high pressure oil is doing is what diymechanic said. I may be misunderstanding this post.

 

I do not know about that just relating what I'm noticing when it does what it does lol

 

It only monitors low pressure oil

 

You're absolutely correct. The 7.3 PSD (Navistar T444E) has 2 separate oil systems. The low pressure system that feeds all the engine bearings, fills the HPOP reservoir, and triggers the oil pressure gauge on the dash, runs off a rearotor pump on the front of the crankshaft. Once that system hits a threshold (8 psi, if I recall correctly), the pressure gauge on the dash goes to the middle of the range (it's essentially a dummy light with a needle on it - it only has 2 positions, on and off). That system operates at 40-60 psi just like the oil system in any other engine.

The HPO system (High pressure oil) is a separate system whose only job it is to operate the injectors. It runs off a reservoir that is filled by the low pressure pump, and uses a swashplate pump run off the camshaft gear (HPOP). The pressure in that system is regulated by the IPR, and the PCM reads the pressure through the ICP. When you connect a scanner, you're only seeing what the PCM (by way of the ICP) sees. The reason for using a mechanical test gauge is that it eliminates the ICP and PCM and lets you see what the ACTUAL pressure is in the HPO system. This system runs between 650 and about 3,000 psi.

Two separate systems, so again, I would recommend you spend the 30 bucks or so to assemble a HPO test gauge and find out what is really going on. If it's building pressure then we go one way, if it's not, we go another. Using a scanner really only lets us see what the PCM is seeing, which doesn't really tell us if the PCM might be the issue, or if the ICP might be.

 

What you're seeing fill up is the HPOP _reservoir_, not the HPOP itself. The HPOP _consumes_ that oil. It's the engine lube pump (aka LPOP) that fills the reservoir. So yes, when that reservoir fills, it says nothing about the health of the HPOP.

 

ok guys it' been a few weeks since I've posted took some time away to think research and decide what the next move was. I Just rebuilt the hpop and put everything back together last night and did a oil change. While I had everything apart I noticed I did have the ipr wired incorrectly. I fixed that put everything back in place and first crank last night truck fired 😃 but then died right off 😥 upon it dying I noticed I was leaking a significant amount of fuel from around the fuel filter. Also the tach was fluctuating while I was cranking would go up to about 200 and then back down and so on. So couple questions can that fuel leak cause the truck not to run since it would be pulling air in as well and could lack of fuel cause that cps to act funny like that or should I look at changing both? Also would all the cranking trying to get the truck started cause a cps to go bad quicker than normal? Thank you guys for everything.

 

Lack of fuel can definitely keep the truck from running. It won't affect the CPS, and neither will cranking the truck trying to get it started. However, if the CPS wasn't a Motorcraft or International part, they've been known to be bad right out of the box (I honestly don't remember, it's been so long).

 

I wondered if you ever got it going again. I believe some time back DYI said to bypass the fuel system and pump directly for a diesel can. Did you ever try that?

 

I will be picking up a new filter today one that has the half inch drive cutout on the to to insure it gets all the way tight and the cps is from ford paid 32 bucks for it. It is a grey one though which I've heard different things about. I'll start with the filter and go from there.

 

I needed a break lol I had spent every day banging my head got too the point I was ready to take it somewhere. Called a couple places to get quotes and one guy told me definitely sounded like the hpop. Checked prices on those and to have one rebuilt at tdi in Louisville they wanted 400 dollars I found the kit for 118 with everything and did it myself. After rebuilding and before I got carried away throwing everything back together I came across a way better illustration of how the ipr wires were supposed too be and I sure enough had them flipped. I never did try the lines the correct way tried doing it from the lines at the tank but with no luck. How I'd previously had the truck parked at our shop you couldn't tell the filter was leaking cuz I was parked above muddy gravel but since then it' been moved on to concrete so after the truck fired Friday night and then died I instantly heard dripping and started tracking the leak and I mean when you crank the truck over it just dumps fuel out of the bowl enough that it fills the valley then drains out the back.