The ICP pressure that you are seeing with the sensor unplugged isn't real. That is a default number that the PCM barfs out when the sensor is disconnected.

The fact that you are seeing low ICP pressure when it is plugged in and high-but-still-no-start with the ICP sensor unplugged means that the HPOP system isn't building pressure. You can confirm this by looking at the IPR%. If it's 85 during all of this, the PCM is trying to build pressure but isn't.

The lack of pressure building could be a mechanical problem (HPOP leak) or an electrical problem (IPR valve wires shorted). I had shorted IPR valve wiring. You can read about the diagnosis and fix here:

http://www.powerstroke.org/forum/6-0-motor-problems/1096562-6-0-harness-chafing.html

If it isn't wiring, an air test is probably the next step.

 

Earlier I wrote this...

...
The lack of pressure building could be a mechanical problem (HPOP leak) or an electrical problem (IPR valve wires shorted). I had shorted IPR valve wiring. You can read about the diagnosis and fix here:

http://www.powerstroke.org/forum/6-0-motor-problems/1096562-6-0-harness-chafing.html

If it isn't wiring, an air test is probably the next step.

Since then, you have posted this:

Ipr pigtail is brand new and connected with heat shrink connectors...

... looked at all the wiring and connections on everything a few times and cant find any issues with it ...

... im assuming i have an hpop leak somewhere because thats the only thing i havent got into ...

... gunna look for leaks in the hpop only thing i havent checked yet

Carquest ipr valve

Here are my thoughts on all of this:

First...
Carquest is almost as bad as eBay. That said... I'd be surprised to find that two or three in a row didn't work for at least a short time.

Second...
If you read at my chafing thread, you would have seen that the IPR valve wiring short that I had was internal to the harness and that I had to cut away the harness casing to find it.

You say that you... "looked at all the wiring and connections on everything a few times and cant find any issues with it". While wiring issues can be a visual thing, they are not EXCLUSIVELY a visual thing. Do you own a meter? Do you have access to an oscilloscope? If nothing else, can you attach a 357 auto bulb to the IPR valve wiring to verify that anything is going to it?

You threw 3 (as near as I can figure) IPR valves at a truck whose wiring you recently changed ["Ipr pigtail is brand new and connected with heat shrink connectors... "] Are you sure that you didn't inadvertently swap the wires? Are you sure that both connections now under heatshrink are conducting at all? I'm not.

The last thing someone touches is usually the problem. You say that the pigtail is new like that means it's gold. It's not gold. In fact - given your current situation - it's more likely to be screwed up than anything.

Third...
You keep mentioning that you are going to airtest it. Airtesting seems more difficult to me than testing electrical connections. That is why I recommend electrical testing first. But, airtesting would rule out an HPOP leak. So, there is no reason to not do that first and - if it passes - go back to the electrical.

 

Ipr pigtail is brand new and connected with heat shrink connectors, looked at all the wiring and connections on everything a few times and cant find any issues with it, i understand that the icp reading is false with the sensor unplugged , im assuming i have an hpop leak somewhere because thats the only thing i havent got into, it ran fine before the oil cooler was replaced and some junk got moving through the system when i replaced it, (im asssuming from the broken screen in bottom of oil cooler reservoir), and it was blowin ipr screens after the replacement, finally got it all cleared out im assuming because ipr screen is clean and intact when i pulled it and the truck was running yesterday! hard to believe something just sprung a leak all of a sudden but with it being a 6.blow i guess i can see it

 

Have you tried a new IPR? Seems like its got the symptoms enough crud in it to clog and bust the screen.

 

Yes, more than likely the IPR is stuck/damaged. Once the screen is gone it is very likely it has been damaged internally. You may be able to clean it out, but it isn't worth the effort since you have no way to test it out of the truck, or if it would function correctly the day or a week after you reinstalled it. This is time to just go buy a new IPR valve and hope that you have no more junk in your HP oil system that might damage the new valve.

 

do you have oil in the truck?

 

theres plenty of oil in the truck, oil caps oem as well as filter, ipr vlave is new, once screen blows i throw em out i already know there junk once the screen breaks

 

how many screens have you replaced?

 

ive replaced the entire ipr valve everytime not just the screen tried it with the first one with no luck and heard how if the screens broke trash the valve it aint worth it so i did, ipr valve is brand new, just pulled the turbo gunna look for leaks in the hpop only thing i havent checked yet

 

Is it an OEM IPR valve or an eBay IPR valve?

 

Carquest ipr valve

 

well considering that it functioned perfectly and then just died and is giving me some pressure (230psi max) from the icp leads me to believe that the ipr is functioning and its just got a leak, i have a fluke 115 meter and a powerprobe, no access to an oscilloscope and couldnt buy a motorcraft one cause the company im with doesnt wanna spend the money, i do a ton of wiring jobs with trailers and stuff and ive never had an issue with the connectors im using, not saying that couldnt be an issue but i dont think it is from everyone ive talked to and everything ive read, and like i said it worked fine all day and then just took a dump, whats the best way to test an ipr valve out of the truck? i havent been able to find any clear way too... also wires werent reversed kind of hard to mess up oem color coding

 

The IPR valve is driven with a 400Hz square wave that has a weak falling edge. You can see it depicted here:

To bench test it, you could feed a function generator with adjustable duty cycle into a transistor or MOSFET buffer or audio amplifier to get adequate current. I have never done this so I can't say for sure what physical motion you will observe from the IPR valve. ...but you will be driving it in the manner to which it is accustomed. Typically, they are tested in the truck.

If you want to instead test the signal at the IPR valve connector - and given the fact that you don't have an oscilloscope - you could feed the signal through a resistor and into your meter with a capacitor across the leads and see if the measured DC voltage roughly changes according to IPR%. If the voltage bounces around, choose a bigger cap.

If your meter has a frequency setting, confirming that you see 400Hz from the signal wire to ground would provide you with some extra measure of confidence.

Regarding wire colors... some pigtails have seemingly random colors and others have the same colors. That was my main thought. My being colorblind means that I often have to rely on diagrams an actual pin positions. I certainly can appreciate (and envy) those who have no such issue.

Attached is Pinpoint Test R for testing the IPR valve.

I'm not saying that it is an electrical problem. I'm not saying that it isn't, either. What I am saying is that concluding that the IPR valve is being provided a good signal without any verification whatsoever is not a good plan. Again... if it passes an airtest, the problem is likely electrical. If the valve is getting a good signal, the problem is likely mechanical. Until more information is available, that is the only thing that I would be willing to say with certainty.

Hope this helps.

_______________________________
Edited to add...

It's worth noting that the IPR valve is supplied VPWR and the IPR signal. So... if you are measuring with an o-scope or meter, you would be better to measure the signal line referenced to ground.

 

The IPR valve is driven

You lost me after "the IPR valve is driven" part.

Is this electronic stuff a profession or just something you enjoy doing on the side. Amazing the smarts we have on this forum! Impressive @djmaguire

 

so im trying to do an air test on this truck, have shop air hooked to the icp sensor spot, turbos off and so is hpop cover as well as both valve covers, pressurize system and got oil coming out of turbo feed line... from what i understand it shouldnt be getting pressure to that side of the system or am i wrong? checked and cleaned the oil pressure regulator in front cover but no change, still getting oil through the turbo feed line.. any help would be much appreciated

 

Did you close the IPR valve? If you don't close the valve you will get oil reversing out of the HP side. Now after saying that, clearing out most of the oil allows for the 100 psi air to find the loose spots in the HP system once you activate the IPR closed. It would not be uncommon for some air to slip out on good oil seals due to the much lower viscosity of air vs oil. If you close the valve right away, you may only notice none or some oil coming out of the injector relief ports. This is normal. Any large oil movement or air leaks are where the problems will be.

 

Completely plugged off oil rails and all injector o rings and anything associated with the rails was fine held 120psi for 20+ minutes, I had an old known bad ipr valve that i welded shut for the air test and was still getting air in the turbo feed with rails and all open (normal system setup)