First let me say, the old adage is true: If it ain't broke, don't fix it. My truck is an early 99 7.3. 455,000 miles and was running ok. I decided to do some maintenance and decided on replacing the ICP and the IPR. I was surprised by the cost of an IPR so I decided to rebuild it instead of replacing it. I ordered the ICP and IPR rebuild kit from RiffRaff. The parts arrived and I went to work. I pulled the IRP out and following the instructions found at Custom Works (You Tube) I disassembled, cleaned and rebuilt the IPR and installed. Next, I removed and installed the new ICP. Started the truck and I have to say, it did start much better. But after about 5 seconds, the engine started to romp, romp, romp, sounded and felt like I had a racing cam installed. The engine set 3 codes. P2111 ICP higher/lower than desired. P1209 ICP pressure peak fault and P1282 IPR excessive pressure.

I contacted Clay at Riffraff and he stated there is air in the system and the truck needs to have some miles put on to purge the air. I took the truck out and drove it 20 miles Highway up to 70 MPH and then a backroad up to 55MPH and returned home. The engine still has the romp. I did notice improved engine performance. However, at idle I still have that engine romp. I pulled the OBD codes. The only code left is the P1211.

I called Clay again and he suggested to unplug the ICP which I did and in doing so, that made no difference. Question: Is the ICP bad? Where do I go from here? I do have the Forscan software loaded in the computer. I'm looking for some direction here to solve.

Help is always appreciated.
Jeff

 

Try reinstalling the old ICP to see if it makes any difference.

 

Check all your pigtails/plugs, monitor your icp and ipr values to see what pcm is seeing/commanding. Drive it another 20 miles.

 

Unplug the IPR. If it starts and runs, the pintle is stuck.

"Rebuilding" the IPR is often a fruitless (and failure-prone) endeavor. If you must throw parts at something for the sake of fixing it until it's broken, bite the bullet and buy a new one - keep an old, non-molested functional one as a spare.

 

If it reacts the same with ICP both connected & disconnected, then the problem is not with the ICP in my opinion. I believe your issue lies within the IPR.

Like Eric said, check all the wiring first though, even back under the loom.

My guess is Cleatus is correct, the IPR is stuck. I image this causing high ICP during idle and maybe even while in rpm since you said it runs stronger.

 

Unplugged the IRP. Stared the engine and it runs.

 

Settled then. IPR's coming back out. It shouldn't do anything but crank with the regulator valve unplugged.

 

Thanks everyone for your inputs.
Clay said to check ICP and DC% at idle. I'm guessing DC% is duty cycle? Can find that on Forscan, I'm still learning how to use it.
Here are the results:
ICP at idle is 725.2 psi
IPR at idle is 14%
ICPV at idle is 3600 psi

I then brought the engine up to 2200 rpm

ICP is at 820psi
IPR is at 12.5%

I then unplugged the IRP and the truck starts and runs. According to Cleatus, the IPR pintle is stuck.
I didn't have the problem before I rebuilt the IRP. I'm guessing to replace the IRP with new.

Comments?
Jeff

 

The ICP values you listed are what is shown when the sensor circuit is open (unplugged) - default PCM mapping.

Do you have your sensor (ICP) and regulator valve (IPR) nomenclature and/or locations mixed up in your post descriptions?

 

I don't think so. I guess I better check again. The sensors were plugged in when I ran the test. I have had Forscan for 90 days and am
still learning how to use.

 

The IPR valve on the back of the high pressure oil pump is not a sensor.

14% and 725 PSI at idle is what a scanner will show when the pressure sensor (ICP - behind the alternator on the LH cylinder head) circuit is open or unplugged. Those are NOT valid data to watch as it's what the PCM defaults to in the event of circuit or sensor problems.

I

 

ICP and IPR plugged in engine running

ICP and IRP unplugged engine running

 

Go into the settings screen of the ICPV PID and change it to Volts. For some reason, Forscan has it defaulted to PSI. To do that, highlight ICPV in the list of added PIDs (the right side) and click the gear icon beneath it.

 

Not only is your IPR not working (runs when unplugged) but now you have a circuit problem with the ICP.

 

I think I'll replace the IPR, then tackle the ICP since it's new.