I'm no expert and don't pretend to understand computer programming for these trucks but it would seem that on initial start you would see full command to the closed position for the IPR to build pressure as fast as you can during cranking. Then maybe the PCM starts to back off the voltage once it sees enough ICP for starting. If your IPR is bad or stuck full open and never closes it would explain low press and max voltage during cranking.

The meter readings are a little confusing. 50 ohms which is what your seeing on the 200 scale should read 0.05k on the 20k scale. I would check the readings again. Is your meter digital, does it auto range and maybe you missed the k or m after the reading?

 

I guess I could see it both ways with 0v or 12v but then you can't apply the 12v for testing without burning up the coils.
Wish I had another 6.0L to verify that.
Yes my multimeter is a cheapo digital one. I had the negative lead on pin #2 and the other on the positive batt terminal and had the truck KOEO. Maybe I did it wrong IDK.

 

Nevermind, brain fart.

 

I could be mistaken, but to ohm the ipr, you need to connect both leads to the ipr pins on the harness. I know that's how I ohm'd my cms and cks, and they ohmd out correctly if you paid attention to the scale on the digital bolt meter.

You can't keep 12v on the ipr for a long time because it will burn it up. I think 10 seconds is the standard, but I've never done it so I could be wrong.

If you pulled the ipr connection, hooked the volt meter to it, and see what volts the pcm is commanding to the ipr. That would verify your Scan gauge readings.

 

This is what I did, pulled the IPR connector had the truck KOEO and the connector already had 12v. Earlier post by AllaboutMPG states initial KOEO IPR if commanded fully closed then why would KOEO duty cycle be 14.84 which as I understand is fully open. I went back and checked my video and noticed the IPR went straight to 84.7% (I know there is no leak in my HPO system).

Thought I followed the instructions given in Rusty post, unless you mean put the leads in the IPR connector lead.

**You can test the electrical side of the IPR like this. Pull out the middle PCM connector and ohm out pin #2 of the PCM connector (yellow with red stripe coloured wire) to the positive terminal of the driver side battery at key-on/engine-off. A good IPR should read about 6.0 ohms.**

Maybe someone can explain exacty where I am putting the positive and negative leads of the multimeter to Ohms the IPR wiring?

 

At the IPR connector pin A with the red wire is power(+). It' hot all the time (key on). pin B is yellow/red wire is the ground (-) and is switched (manipulated by the PCM to open/close the valve). That's what's making it hard to figure, the ground is switched. You can apply battery power to the red wire and ground to the yellow/red wire at the IPR with the connector unplugged to close the IPR. It's also possible to back probe the yellow/red wire at the PCM connector (with it connected) to ground with the key on to close the IPR.

Seems to be some different info on how long you can leave 12v on the IPR. A couple of the guys on here I trust a lot say 2min is a reasonable limit but even longer shouldn't be a problem.

When doing the ohm measurement leave the key off (correction, key should be on). It's just a resistance check through the solenoid coil.

 

Here's my notes. Probably copied from FTE somewhere..

4 ways to close the IPR:
1. Software like IDS to comand it closed (maybe AutoEnginuity will do it)
2. Buy an IPR connector and wire it up to apply switched power to close it: Red wire switched power Pin A: apply B+; Yellow/red switched ground Pin B: Apply B-
3. You can close it by having the key in the RUN position, and jumping pin #2 of C1381c (the middle of the three PCM connectors between the driver side battery and the inner driver side fender well which requires the battery cover removed to access) which will be a yellow wire with red stripe. This is the ground side wire to the IPR.
4. Tool to close the IPR: Automotive Tool Web-site - DenLors Tools; OTC 6764 Ford Diesel 6.0L IPR Controller / Tester

OTC 6764 Ford Diesel 6.0L IPR Controller / Tester | Multimeters, Amp Clamps, Test Leads tml


Don't hold the IPR valve closed for more than 2 minutes. I have been told it is OK to do it longer, but I don't want to put someone elses IPR valve at risk.

 

Damn so it's normal for the IPR connector to show voltage.
I have the OTC-6764 comes in pretty handy except for the noisy fan and trying to hear an air leak so I'm good on closing the IPR.
I'm still confused on how to ohm pin #2 of the PCM connector though, bear with me, electronics not my strong suit.

 

Just disconnect the center PCM connector, 1 lead on pin#2 (yellow/red wire) and the other lead to the +battery post. Notes did say key on engine off, not sure that's necessary..(yes it is) highest scale on the meter (or auto range if it has it). I saw one of your posts that was very near 6ohms, sounds ok to me if that's what you get. Bismic has posted he thought between 3 and 15 ohms is ok. Hope I didn't side track you, just posted that because I though that it was worth a look while you were right there...

 

Now I'm confused because I trust anything Rusty (Eric) posts without question. Eric, can't you ohm the ipr with it sitting on your kitchen table by just connecting the two leads to the ipr pins? Of so, why does one lead have to be on the battery?

To 350, default for the ipr is fully opened. So 0% is default and 85% is fully closed .... Or as close to closed as Scan Gauge ii can measure. No poster has confirmed that koeo is fully closed on the ipr. Someone said "if" it is, then the voltage would be 12v.

 

Thanks Brian , yup you can check the IPR on the workbench by reading across pins A&B, for sure the way to go if you have the IPR out of the truck. The idea here is it's quicker/easier to check at the PCM connector than getting behind the turbo and getting the meter leads on the IPR connector pins.

The yellow/red stripe wire is the ground side, the other side is hot all the time (battery voltage) so the other lead goes to the + on the battery with the key on to close the circuit.

 

Thanks guys this was useful info, I will keep troubleshooting. Next I will get a compression check on all cylinders, Good idea or not?

 

Good to have the numbers I guess but here is a quick way to check:

 

Awesome, that is. Quick and easy check and hopefully I have no issues. Side note got my FICM from that guy..........verdict is still out but seems to work great.

 

Awesome, that is a quick and easy check and hopefully I have no issues. Side note got my FICM from that guy..........verdict is still out until the truck runs but seems to work great so far. He puts out some good videos, very helpfull. Double post ooops damn iPhone