The thing you are describing as the IPR is actually the ICP sensor. You can't ever get a start by unplugging the IPR valve because it would always be dumping pressure then. You unplug the ICP sensor if you suspect that the sensor is bad. This can help in the troubleshooting process - if you have a bad ICP sensor. It does this because the PCM will use an inferred ICP value when it doesn't see a voltage signal from the sensor.

All IPR valves are at the back of the engine near the firewall - off of the discharge of the high pressure oil pump. They are "duty-cycled" closed so that the desired ICP pressure can be reached.

Also, the scangaugeII is not a great code reader. Downloading ForScan to a smart phone and getting a good OBDII adapter would get you a better code reader.

We need to see cranking data when it isn't starting:
cam/crank sync
FICM sync
cranking rpm
FICM LPower (logic power)
FICMVPower (vehicle power)
FICMMPower (main power)
ICP volts
ICP pressure
ICP desired pressure
IPR % duty cycle
v-reference voltage

All of the above PIDs should be available from the scangauge

 

Thank You sir will my truck crank if the ICP sensor is unplugged? because with it unplugged it Hit 1000 Psi and I only need 500 psi to crank it or how does that work

 

Ok I got a 2004 to 2005 f250 6.0 that is a no start... The Icp is on the passenger side of the motor so I'm guessing 05 but title says 04. It has stumped some of the best mechanics around... One day you go out and turn the key it will fire right up. One day you may try to crank it and it won't crank for days. It really has a mind of its own. Sometimes when it rains it won't start. I have got it to crank before by unplugging the glow plug module and plugging it back in... Unhooking the batteries for about 30mins and hooking them back up. Sometimes a gas rag will do the trick other times nothing seems to work. My scan gauge shows no codes but when I try to crank it Ipr is under 300 I unplugged the Icp sensor and it hit over 1000psi but still didn't crank. I'm fixing to hook a charger to the Batteries and try it again with the Icp unplugged and see what it does. Can Anyone Please Help Me Out...

I don't know if I got a bad connection somewhere or maybe a lose ground. Maybe a bad plug on the Icp sensor.

 

The ICP sensor is a known reliability issue. More so when it is located behind the turbo than when it is on the passenger valve cover, but even there it can fail. If it (the sensor) shorts out it can cause a no-start. By disconnecting it, the electrical short is removed and the PCM estimates the starting value. It will assume a value above 500 psig and it will start if that (the sensor electrical short) is the only issue.

The randomness you describe may or may not be the ICP sensor though. We would need to see readings when the engine won't start to get a better idea of the issue(s).

 

It won't crank with it unplugged but it reads over 1000 psi... plugged in it reads under 300 psi.... Voltage is 10.7... how can I test the ICP to se if its shorted out?

 

I gotta finish setting up all the pids in my scan gauge and I'll list all the readings you requested when I'm done. Thank you for helping me man I an currently unemployed with a wife and 2 children and I don't have the money to take it to a shop so I am having to learn and troubleshoot in the dark I know very little about this truck nut I can't get a job with no way to get back and forth

 

It won't crank or it won't start? Two different things

 

Alright so it spit the code P2285 That was probably from me unplugging the ICP sensor and trying to crank it.
KOEO Trying To Crank
FLP 12.0 10.0
FMP 48.5 48.5
ICV 0.23 0.50
ICP 0 267
IPR 14.8 84.7
CVI 4.97 4.97
VLT 12.2 10.4
SYC 0 1
FSS 0 140

 

Jamie has an excellent point.

Not cranking means the starter isn't spinning and the engine isn't turning over at all.

I assumed from the wording in your first post that you really meant that it wasn't starting. I should not have just assumed, I should have asked like Jamie did.

Could you confirm that the engine is ALWAYS turning over, it just isn't starting?

From your post above, you are getting SOME pressure in the high pressure system, so clearly the engine is turning during that test.

 

Wait a second... I gotta turn the Key? and Make the motor make noise! Lmao Yes the engine is turning over, it just isn't starting

 

That's a lot different then not cranking, whish is what you kept saying. The distinction is an important one.

Carry on.

 

The truck was running fine before it rained... Its rained for the past week strait now it wont start...

 

Didn't mean to sound condescending or anything, but actually getting a no-crank is more common than you might expect. It is hard to troubleshoot over the internet, so communication needs to really be exact.

So from your data, it sure seems like your issue is low pressure in the high pressure oil system. You may also have an electrical issue, so troubleshooting that will probably be necessary to avoid just replacing parts.

When you disconnect the ICP, the PCM will assume a value. When you try to start, you will get a reading of 850 psig to say 1100 psig from the PCM. When you have a leak or a bad HPOP, you won't be able to start because the actual pressure isn't high enough to get it to start.

One thread, a person had bad wiring to the IPR valve. It was constantly open because of the electrical short. You need to realize that an IPR duty cycle reading is only a commanded value. It tells you nothing about the valve operation itself. Come to find out, a shop that had recently worked on his truck BUTCHERED the IPR wiring. It was hard to track down because you shouldn't have bad IPR wiring unless someone has messed with it. We have no way over the internet of knowing that history!

Jamie would have to walk you through the electrical testing to ensure that the IPR wiring is intact. I have the electrical diagrams, but I hate troubleshooting electrical problems.

My approach would be to air test the system. It is fairly easy since your ICP sensor is on the passenger valve cover. Lots of posts and videos on air testing. The biggest issue to this testing is that you need to command the IPR closed for this testing to be valid. I can post several options for this if you want.

Another option is to get the fitting so you can remove the IPR valve itself and install the fitting, then you can air test from that fitting. It eliminates a bad IPR valve from the troubleshooting.

On a late 04, your issue is likely to be (in order of priority as I see it):
leaking dummy plug(s)
bad HPOP
bad IPR valve
leaking standpipe(s)
leaking injector o-rings
leaking o-rings elsewhere in the high pressure rail

 

If I am seeing it right ur Icp is only 267 if thats the case it wont start it takes atleast 500 to start. If this is the case then you may have some more deeper problems.

 

I would almost be willing to bet you its in the wiring somewhere... The reason I say that is because this is the 3rd time its done it when it rained a lot... That's also another reason its stumped so many shops... Last time it came a big rain it gave me the same trouble... I unplugged the ICP and I Unplugged the glow plug module plugged them back up and the truck started like brand new. Another time it rained it did the same thing and I unplugged damn near everything and put that clear stuff thats suppose to get the moisture out on all my connectors and it fired up like new.... I Also Have A Cluster Issue that has been a headache sense day 1... My cluster will go in and out when it goes out usually the parking brake light will pop up and BAM! Radio, Power Windows, Dome Lights, And All Gauges stop working... Sometimes you pat the dash and it will all turn back on sometimes wont work for days...

 

When it starts It runs great. Its only got 120,000 miles on the truck. Has EGR Delete and has been bulletproofed before I bought it The guy that had it before me must have had a pocket full of money because there isn't any upgrade left that can be done to prevent any major issues.

 

There is always something that can fail. Hopefully it doesn't happen, but never say never!

Just an fyi - the instrument cluster is on the 5V reference circuit. Instrument cluster issues, especially related to water intrusion and electrical shorts, can result in a no-start.

That said, the data doesn't lie. I assume the data you posted was when it wouldn't start (since that is what I asked for). Your data says that you have an issue with the high pressure oil pressure. Now, it could be the same issue as I described above. The IPR duty cycle command (84.7 is max) is telling the IPR valve to close at the max duty cycle. It may not actually be doing that.

The data also seems to indicate that the ICP sensor is ok (or maybe the issue is intermittent perhaps). You might check the ICP sensor connector and see if it has oil inside of it. When the sensor begins to fail, they can leak oil into the connector and cause issues electrically.

 

I would send the cluster in to circuit board medics. I wouldn't put up with that.

Also, many times the root cause is water intrusion and that can come from a poorly installed windshield.

 

If it does have water intrusion and something is shorted out could it be causing the high pressure oil pump to not turn on? There is no oil in the ICP connector its clean as can be. Also if data is pointing to oil pressure could changing my oil help the issue? I know once before It had a Start Issue. I changed the oil and filter and it fired up like new. Normally When I go to crank it, It will start withing a couple of seconds but like today. "After It Rain" you will run the batteries down and it will never start. Could Water Intrusion Cause False Data When Attempting to Start It? If So Would putting that clear stuff back on all my connectors and unhooking my batteries for about 30mins reset and solve the issue like once before?

 

If I do have a leak in the windshield how would I find what its getting into to cause this issue or how could It be fixed

 

Since you have cluster issues, I would remove the cluster and send it in. Look for signs of water with the cluster removed.

I just don't see how water can get into the engine well to affect the wiring under the hood. Maybe it could get to the wiring along the firewall. If there were some wire chaffing in the engine harness, then maybe it could affect readings. I still keep coming back to the data you posted. V-reference looks good. The ICP voltage matches exactly the pressure that the PCM is reporting. It looks like an issue w/ low pressure.

So was that data collected during or after a rain? If not, you have an issue that might be IN ADDITION to the rain issue.

So many things are possible, just not likely. Still the only way to resolve the issues is by digging in, collecting data, and inspecting things - when the problem is occurring.

 

One other thing - weak batteries (even one weak battery) can cause weird issues to happen.

I always make sure that the batteries have load tested good (both independently) before I begin no-start troubleshooting.

 

Yep! Batteries can go bad and you end up with this. I just replaced mine after 2 years as they don’t seem to live longer than that. Of course, it was 100% warranty, so I saved money there!

 

I been hoping it would dry out and crank like usual but I've had no luck getting it started... I go to crank it and my oil gauge acts like it wants to take a few minutes to show that I have base oil pressure. I Gave it a tiny shot of butane in the air intake and it sped up the cranking but without base oil pressure it didn't do anything. Once the base oil pressure showed on my gauge I gave it another little shot and It tried to start ran for maybe a second or two and died back out... I't still wet from the heavy dew fall here in Mississippi I don't know what to do with it anymore Anyone wanna buy a 6.0 haha

 

It seems you have confirmed you have a real oil pressure issue. It could be an issue w/ the low pressure oil delivery and pressure or it could totally be related to the high pressure side.

You need to do an air test. Lots of videos on this.

The late 04 model year has the following weak areas in the high pressure oil system (in order of most frequent to least frequent):
- Dummy plugs
- HPOP
- IPR
- Standpipes
- Oil rail and injector top seals

If the Dummy plugs and Standpipes have ever been upgraded, then they probably aren't bad. You can tell if they have been upgraded, they will have a 12mm hex head for removal and installation.

The HPOP can be condemned during the air test if you hear air leakage at the oil filter canister.

You might want to remove the IPR and inspect it before doing anything. Sometimes it can get plugged. It has a screen on it, but still you can get trash in it and the screen can actually get sucked up into the valve.

I still think you need to charge and then individually load test the batteries. More people have battery issues than you could ever imagine. Also, most seem to deny it until they load test!

 

I'm with bismic1. Unplugging the ICP sensor deferres the pcm to anywhere from 850 to 1000+ psi. But even in that configuration, you still have to have 400-500 actual psi to operate the injectors.
Hook a direct reading gauge up in place of the ICP sensor and that will tell the truth.