My 2003 Super Duty 7.3 with 114,000 miles dies instantly while driving down the road. It ran great and never had any major issues until one day it just died. All the symptoms of a CPS. Replaced CPS and ran great, towed my boat, and drove for a week, then it just shut off like I turned off the key as I was driving about 45 MPH with no variance in throttle. Pulled over to the side of the road and installed my "spare" CPS. No start, no tach, but all the other lights and gauges worked...it was dead. Called for a tow after an hour of fiddling with it, and by the time the tow truck arrived I decided to try and start it again. It started right up, and ran like nothing was wrong. I went ahead and had it towed home because I didn't want to be stranded again in the middle of the night. I have started it several times in my driveway and left it run for 30 minutes at a time with no problems. I connected a code reader and it is registering no trouble codes at all. I even put the old CPS back in to see if it was working, and it started right up. Seems like it will die and not want to start up until it sits for 1 or 2 hours. I am going to check the harness from the CPS to the main harness for shorts. Any ideas???

 

Hi Edgeotime,

I'm gonna move this down to the 7.3L PSD forum, the guys down there will better know how to handle this one...

 

Bad IPR. That's your culprit.

If the next time the truck dies, and you go to crank, keep the key cranking for 20 seconds. You'll set a low ICP fault, which will mean your IPR is stuck and not allowing oil pressure to build.

I know this because the exact, and I do mean the exact identical symptoms occurred to me a few years ago.

 

Sounds good Pocket. If that doesn't cover it, the last link in my sig might have something of use.

 

I have also experienced that same situation twice. IPR both times. Easy thing to at least pull out and clean. This will show you how

https://www.ford-trucks.com/forums/a...1&d=1335106783

 

Thanks Guys. Semper Fi CaverJoe. I'm still working on the servicing of the IPR, and waiting on new O-rings for replacement. I will let you know how things work out. Going to take a while to build up confidence in driving the truck again.

I was talking with a Ford parts guy, and he said that often the HPOP is a culprit as well, and that since my IPR failed, that my HPOP may need to be replaced. Have you guys had the same experience? Or should the HPOP be fine?

Appreciate your help!

 

It's not the HPOP. It's almost never the HPOP, although a lot of them have been changed when ICP codes show up. Since they mostly come with a new IPR, the "HPOP change" seems to cure it. We did see a rash of the rebuilt HPOP's fail a while back, so in some cases the original is better than the replacement.

While you're waiting for the IPR stuff, be sure to check the wiring going to the IPR and the ICP connector. Shorted wires near the connectors can cause similar symptoms. So can chaffed wires below or behind the 42 pin connector (square box with a bolt in the middle of it over the driver side valve cover under the air intake).

 

Semper Fi Chris. I changed oil while I was waiting for my O-rings, reinstalled the IPR, it started fine, which it does when cool, and started changing out the oil in the HPOP several times until I got clean oil. It started every time as I was changing out HPOP oil, until...it got hot. On my last top off of the HPOP it would not start. Oil was very hot on my last drain of the HPOP, so I guess that whole area gets pretty hot, which I assume is normal. I went out and started it no problem about an hour later.

I read another thread from a different site and a guy narrowed his problem down to the IPR connector. He would ice the connector, disconnect it and reconnect it and would be able to start again in 5-10 minutes. I hear that you can just get the pigtail with the fuel bowl connector as well that then connects to the main harness, so I guess I will try that next. He never posted what his final solution was.

Strange that after 114,000 miles the truck would just start shutting down, but that is the way things happen.

 

There is the possibility that the winding of the IPR solenoid is going open when it heats up. The winding resistance should be somewhere between 10 and 10.8 ohms and steady (no fluctuation).

 

I had a similar problem with my '03 7.3 PSD... Driving on the highway it just died, no gasps for breath or anything. Coasted off into a parkinglot, called a tow to the stealership 'cause I didn't have the time or interest to mess with it.

Turns out the dealer said it was a chaffed wire in a harness on the driver side valve cover... something I probably never would have found. I guess the vibrations from 115,000 miles finally wore through the insulation.

Anyway, if you don't fix it with any of the previous ideas, take a look at the wiring harnesses.....

FireGT

 

Just seeing what the culprit will be

 

I got the IPR cleaned and replaced with new O-rings. Checked the ohms cold and the IPR solenoid was fine. The solenoid on the IPR may be faulting when it gets hot. Checked the wiring up to the 42 pin and didn't see any worn wires, and also cross checked continuity between the wires going to the CPS and IPR and didn't get any indications of shorts. Took it for a drive on a road with little traffic...it died as soon as it got warm from running again only about 5 miles down a hilly road. Wouldn't start and there was no tach movement and no check engine light. I had to sit and wait a little over an hour for it to cool down, then I started it without any problem and drove home.

I went to the local diesel shop, and they want me to bring it in for diagnostics. Said it might be injector O-rings, but I don't have any smoke, even though I did not open the fuel bowl when it died to see if I had black fuel. Also suggested ICP may be bad. Told them I did the rebuild/cleanout thing on the IPR and they said to always replace with new, and that the cleaning only works for a small percentage.

The Injector O-ring baffles me, because the engine ran great up until the day it just shut off on me and I thought it was the CPS. It was not the CPS, but the fact that I didn't start it for an hour and a half later. One would thing if it were Injector O-rings that performance would diminish over time vs. just shutting off one day, like turning the key off.

Guess I am going to replace the IPR with new and also just do the IPC as well. The diagnostic is $120 alone which just about covers the IPR. Not a lot of bucks for the diagnostic, but things are tight right now. Should I make sure the IPR is FORD?

 

you can get one from Clay, (riffraffdiesel). Its not your injector o-rings

 

I would replace the IPR solenoid first. Rule it in or out.

 

I would replace the IPR solenoid first. Rule it in or out.


Can't get just get the solenoid, right? I will order a new IPR, and let you all know what happens. Thanks!
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