2005 6.0 No Start

[JUGGS]

My truck was running perfectly up until Thursday night when I got home from work. I shut her off so I could run in the house for a few minutes before heading back out. She hasn't ran since...just cranks and cranks. We have family about to be here for most of the week so I'm not going to mess with it, instead I'm just going to take her down to the Ferd house here in town. I've dealt with them a few times and they seem OK, but I want to have as much info as I can, to compare my notes with theirs.

What I have is:
FICM 48.5 with key on, but not cranking. 48.0 steady while cranking.
ICP 0 with key on. 319 - 321 while cranking.
IPR 14.4 with key on. 77.6 max while cranking.

I tried unplugging the ICP and it stilll wouldn't start, but the ICP number jumped into the 1500's while cranking with it out.

Like I said, she gave no indications there were any problems until I tried re-start her the other night. The mods in my sig (STC Fitting, screen upgrades, etc.) all were done about 25k miles ago.

Any advise will be appreciated. Thanks guys.

[kaya@bernhausen]

with the icp disconnected you're only getting a calculated value of what it should be. it is not actual.
the ipr reading you have there was not taken with the icp disconnected, was it? it is very important to know this.
if the icp was connected, for whatever reason, your ipr is not being commanded full closed when it should be. this would lead one to believe that the icp were the culprit, since it is the main input for ipr duty cycle. but that would contradict your reading you have.
just noticed you're running a tuner. return it to stock first and see what happens. the tuner sometimes gives a lower icp value to trick the pcm.
recheck your readings with it sock.
if they don't change, i think what i'd do here is manually close the ipr by supplying 12v and ground to the valve. crank the engine. in theory, it should start. BE CAUTIOUS! you must remove the power source from the ipr immediately, as you don't want it running full closed for more than a second.

[JUGGS]

Originally Posted by kaya@bernhausen

with the icp disconnected you're only getting a calculated value of what it should be. it is not actual.
the ipr reading you have there was not taken with the icp disconnected, was it? it is very important to know this.
if the icp was connected, for whatever reason, your ipr is not being commanded full closed when it should be. this would lead one to believe that the icp were the culprit, since it is the main input for ipr duty cycle. but that would contradict your reading you have.
just noticed you're running a tuner. return it to stock first and see what happens. the tuner sometimes gives a lower icp value to trick the pcm.
recheck your readings with it sock.
if they don't change, i think what i'd do here is manually close the ipr by supplying 12v and ground to the valve. crank the engine. in theory, it should start. BE CAUTIOUS! you must remove the power source from the ipr immediately, as you don't want it running full closed for more than a second.

Thanks for responding. The first thing I did was set the truck back to stock, then I took readings with ICP connected. After, I unplugged it to see what would change.

The truck left on a tow truck a little while ago. There's no way I'll have time to do anything with it and I'll need it running by end of the week so I figured this was the best thing.

I just heard from the shop and they won't get to look at it til Wednesday so I guess I'll post back here after with what they say. I'm going to want to find out from you all if it sounds like these guys know what they're talking about.

One good thing...with all the research I've done, I'm beginning to finally understand more about this important part of my truck. First it was the EGR system, now the HPO system. Maybe my fuel system will fail next

[JUGGS]

Originally Posted by JUGGS

Thanks for responding. The first thing I did was set the truck back to stock, then I took readings with ICP connected. After, I unplugged it to see what would change.

The truck left on a tow truck a little while ago. There's no way I'll have time to do anything with it and I'll need it running by end of the week so I figured this was the best thing.

I just heard from the shop and they won't get to look at it til Wednesday so I guess I'll post back here after with what they say. I'm going to want to find out from you all if it sounds like these guys know what they're talking about.

One good thing...with all the research I've done, I'm beginning to finally understand more about this important part of my truck. First it was the EGR system, now the HPO system. Maybe my fuel system will fail next

**I just realized I never mentioned that I'm pretty sure it's HPOP-related. The STC fitting and screen(s) have been upgraded for some time now.

[Jarrod B]

Well I was about to mention sct or standpipes. Or ipr.


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[dannyboy950]

Juggs your problem is an hp oil leak but you mention something I have been investigateing for about 6 months now with no real soloution.

You mention testing with the ICP unplugged yet showing an increase in ICP recorded pressure. At first I just thought it was a missread or glitch but I became seeing more and more posts stateing the same thing. So my curiousty got the best of me and I began investigateing.

A unplugged ICP throws a default setting 750 psi which allows the truck to start and run as long as the HPoil system is actually working even if not to full capacity. Since it is a default that pessure is all the pcm should be able to see. Yet testing a number of systems on live data logs the pressure shows an increase in pressure accoding to corresponding throttle increase.

The question is how, the ICP is unplugged!! and as far as I know the ICP is the only signal the pcm sees.

The only thing I can figure is it is inferred fom other readings but not shure what readings. I assume from pedal command and vss but not shure whatelse.

Since I no longer have access to any vehicles to test on I leave these thoughts to other techs to verify or condemm.

Juggs I apologise for hijacking your thread but it fits somewhat.
Keep testing for a small HPoil leak I think that will fix your problem.

[kaya@bernhausen]

personally, i don't think it's a leak. you'd see ipr full closed if it were, always. for some reason, the pcm is not closing it. it must be either the input (icp sensor) or the pcm itself. however, if it were the icp sensor, it would be contradicting the reading on the monitor and ultimately, the pcm. which really only leaves the pcm.
while the problem were occurring, commanding the ipr closed manually, right at the valve, and cranking would confirm this if it did fire up.
this is also a problem hot or cold, since you say it hasn't run since.
this is all under the assumption that the readings you have provided are accurate.
something tells me, unless the dealer has a decent tech with a fair knowledge on the 6.0l, that this may go misdiagnosed. please do let us know what they say before any repairs are performed

personally, what i'd do if this were at our shop, is install an ipr blocker and crank. see if pressure builds then. if it does, i know which route to start to follow. if it doesn't, ipr blocker still installed, pull the valve covers and air it up. if no leaks were detected, i'd be looking at an hpop. not very common on an 05 though.
this would all be after confirming low side oil pressure, of course

dannyboy, you are right. icp is inferred when a fault is found by the pcm. a safety precaution i reckon. as for the inputs for the inferred reading, i'd suppose app, eot, rpm, map, maf. the usual inputs for load cal.

[dannyboy950]

I guess my next question is to find out WHY it does it. Wanting to know why allways kept me in trouble when I was a kid LOL

[05 six-0h psd]

not trying to hijack the post, but the exact same problem happened to my 05 on thursday as well...ran fine and then when i went to start it back up it just cranks...once i get home from visiting family im going to tear into it and see what i can find..

[redlinedsix]

With out the intent to highjack.

From what I understand, on an 05 the IPR is located on the right of the HPOP, in order to test, ground it and apply twelve volts. to get to it is a a tight fit, what method is best used in this situation? finding where the pigtail come out at some where?