97 F Superduty stops running

[JR Sparky]

Having a problem and I can't find the solution. My 97 DRW 7.3 Turbo, 5 spd. manual, starts fine, runs well for 30 minutes or so on highway and the stops when dropping to idle for a stop. Will crank very quickly, tach is responding but will not fire. Have fuel in the filter bowl, filter is new, batterys are hot, 12.6 & 12.7 volts and I don't have a clue. It will start using starting fluid and repeats the cycle. Will not fire by itself until everything is cooled down again. Has anyone a clue as to what is going on ???? 60,000 miles on odometer

Appreciate any help given and would like to find a good mechanic in Lake County Florida as I'm all out of ideas and really don't want to take it to a Ford dealer. Any references?

 

[BIG JOE]

CPS getting weak ?

Sounds like those symptoms.

Joe

 

[DaveBen]

That is what I thought, but JR says the tech is working when cranking.

Dave

 

[BIG JOE]

That is what I thought, but JR says the tech is working when cranking.

Dave

True.. but I've seen them, when they heat up.. if it's getting weak.. at RPM the PCM can't/doesn't read the Cam Position.. engine shuts down. Let it set, or crank it.. the PCM sees enough signal.. starts/runs till it happens again.

If JR hasn't R&R'd the Black CPS.. with the Grey one.. It's a good place to start the Trouble Shoot ?

Joe

Also: Cleaning up the Batt posts & clamps wouldn't hurt either. Speaking of Either.. Don't use Ether on these PSD's. JMO.

 

[Patrick Feeley]

Also, you may want to check the Injection Pressure Control (IPR) o-rings or some other internal High Pressure Oil System leaks (such as a bad top o-ring on an injector). Hot oil will bypass bad o-rings easier than colder, thicker oil and cause a loss of HP oil pressure. IPR o-rings are a cheap fix (about $30), so I'd start looking there. Of course, using ether is not good (make sure your glowplugs are disabled!). Cheers!

 

[JR Sparky]

IPR rebuilt

Thanks guys for the advice on the IPR, I didn't have a clue about it. Found Viton O-Rings at NAPA, (no body had the kit in stock) and the unit has been removed, cleaned, replaced the rings and cleaned the connector.
Used die-eletric grease on the connector body to try to inhibit any moisture. While all of that stuff was out I also replaced the rubber fuel lines. Used the wine bottle cork to stop the loss of oil from the HPOP reservoir and only had to add about 1/2 quart to top it off. Temp was 80* + so it cranked right up.
I do have a grey CPS I will install in the A.M. before taking it on the highway for a trial run. Thanks again.
J R

 

[DaveBen]

I am glad you finally figured it out. I hope you get a lot if miles outa your rebuilt IPR.

Dave

 

[94f450sd]

Injector orings will do this as well.what does your fuel filter look like? Also clean the fuel pressure regulator screen.

 

[JR Sparky]

Fuel Pressure Screen

I forgot to list that procedure. I used several q-tip sticks and WD 40 to clean the screen from inside the bowl. I kept at it until a q-tip came out spotless. I think the screen is clean. I hope all of this works and it isn't injector o-rings as I think that process may be over my head. Thanks for the advice.

 

[JR Sparky]

And the saga continues. Replaced the CPS this A.M. with the new grey one and took her for a spin. Got her up to temp on the highway and stopped to fill the tanks, did not stop running at idle. After 10 or 12 minutes attempted to start the truck, SOS.
The only thing I can do at this point is change the oil and filter (6 months old, maybe 1500 miles). The truck wasn't started for 3 months and was parked outside, don't know if that affects anything or not.
If this problem persists does anyone know a competent diesel mechanic in the Leesburg, Clermont Florida area? I am at the end of my patience and skill level.