Backstory....I have a 2002 7.3. Owned it for several years and many reliable miles...until lately. Currently has 225,000 miles. I recently did the injector cup replacement due to fuel in coolant. All went well. Back together with new o-rings and everything was running fine. A couple weeks after the cup replacement, the truck dies in the middle of the road. An inspection of the usual suspects led me to find that the tin nut had backed off of the IPR. Luckily I keep a spare nut in the same box that my spare CPS is stored in. Another week or so goes by and the truck cuts out going down the road like someone shut the key off. It happened so fast that I couldn't even note what the gauges were doing before it was acting like nothing happened. Now the truck is cutting out a lot but just when first starting in the morning. It will start and run for about 10-15 sec. then die and cut out several times until it eventually the cutting out quits and it runs fine until it everything cools off again. Also when the engine cuts out, I can hear a clicking from the fuse panel. The only code that it will throw....and it does not throw it every time, is a P0231 "secondary fuel circuit". This is very spiratic and I really need some help figuring it out.

What I've done so far is:
Checked the fuel pump fuse and inertia switch. Both of which are fine and showing good voltage under load.
The fuel pump pumps fine and refills the fuel bowl fast. I have not checked pressures yet, but it never seems to cut out when the truck dies.
I ran a fused jumper wire to fuel pump and unhooked the normal wire.
I've checked all of the usual spots for a chaffed wire.
Swapped CPS just to be sure.
Checked for moisture on back side of fuse panel and on GEM module.
Wiggled just about every wire i can get my hands on.
Tapped on the CPU and the Fuse panel with the back side of a screw driver and neither makes a notable difference with the cutting out.

Could this be a problem related to the IPR as I didn't have any issues until the tin nut came loose? If not, I'm open to other ideas. Any help is greatly appreciated!

 

Does just the motor die or do you lose all electrical power?

 

The motor dyes abruptly without warning. All electrical appears to stay normal.

 

OK, that eliminates a couple things.

Maybe the moderators can move this thread to the 99-03 7.3L PSD forum, it will get more traffic.

You would be in a great position if you had access to software that could log and trend I/O values while you drive. The intermittent nature of your problem is going to make a generic scanner fairly useless. Any chance you have access to anything like that? You don't want to throw parts at this. It could be anything from a hokey sensor to a bad PCM or FICM. Trending will show you what is dropping out.

If you can reliably recreate the issue, you may want to work with a local diesel or Ford truck shop. A ride along with a tech plugged into your truck may be very educational.

 

If you suspect an IPR issue you'll need to monitor the IPR Pid while driving or trying to recreate the concern. Agreed, this should be in the diesel forum. The P0231 is probably a memory code caused by it shutting down. I'd look elsewhere if you have a good ground & power to the pump with proper fuel pressure. occasionally we would see the engine harness chafed on the inner fender or valve cover & will cause all sorts of odd concerns.