[FaithH]

We have a 2003 Ford F-250 Powerstroke Diesel. While my boyfriend was driving to work around 4:30am, it shut off while driving. (And would not come back on.) He changed the CPS, and he also noticed that the starter came loose and he had to screw it back in. It started and drove the rest of the day fine. The next morning at about the same time while driving to work, it did the same thing. He ended up just hitting the starter and it finally turned over and is running again. Any suggestions as to what could be the problem?

 

[Oneof6]

Faith, not enough specificity with no vehicle information other than year to help much. But I will try. A CPS will sometimes shut a unit down. But a new one rarely goes bad the next day. A loose starter is common but it wont shut the unit down, if loose enough it could prevent a restart by disengaging from the engine. So, it appears that both CPS and starter are unrelated to the shutdown. If it were me, my next check would be IPR solenoid tin nut tightness and wiring. A loose IPR nut or old/bad IPR solenoid will shut down an engine when the solenoid gets hot, then allow it to start and run when it cools. The time gap between to hot to run and cooled off enough to start is often enough for an owner to change something unrelated and think that was the fix, for a while.

 

[klhansen]

Need to know if you have a 7.3L or a 6.0L engine. Both were available in the '03 models.
I moved your post to the 99-07 General Questions Forum, but if you tell us which engine it has, I can move it again to the appropriate Engine & Drivetrain Forum.
Welcome to TheDieselStop.

 

[FaithH]

Sorry, it is a 7.3L. I thought I had written that in the post.

 

[Oneof6]

Faith, the advice given so far is applicable to and a common problem of a 7.3 engine, chain of symptoms similar to events you described.

 

[jleedog]

My money is on a bad IPR. Make sure you replace with motocraft parts only.

 

[ArcticDriver]

If it ran the rest of the day fine then it might not be the IPR, unless he just drove short distances with cool downs in between.

But one way to test the IPR prior to replacing it for $180 is to pour water over it the next time the engine shuts down. This cools it off.

Hitting the starter to get it to engage is not directly responsible for the engine shutting down but could indicate a 12v issue.

Meanwhile, if it always dies in the same place, maybe he should choose a different route.

 

[Bamaman1]

The IPR is behind the fuel filter a little to the right, and it's small with a wire sticking out. When the magnet in it wears/weakens, the thing's toast. It'll make the engine do strange things like rpm's going up and down. The test is to unplug it and see if the engine smooths out. Only put a Motorcraft brand--regardless of the price. I used a Standard brand once, and it was junk. It's a 2 minute job to replace the IPR.

 

[jleedog]

I'm not sure it will run with the IPR unplugged, I could be wrong but I've never tried it. The ICP you can unplug and it will use a default setting.

 

[klhansen]

If you unplug the IPR the engine will die like you switched off the key.

 

[Oneof6]

The default IPR pressure is zero psi, the coil is an actuator of the mechanical valve, unplug it and it goes to default zero. A coil that is bad doesnt actuate and the valve goes to default, no fuel to the injectors.