I enjoy reading all the scenarios that are posted here as there is a wealth of knowledge provided and experience... I haven't seen anything like this in reading all day so I better ask...


I'm coming into St. Louis from San Jose, Ca. and a long and uneventful trip (#7 trip) with my 99 F350 7.3 Dually pulling a 50' trailer weighing 20K and all was good until it started raining around Springfield, Mo... I'm just cruising along @ 70 when BOOM! and I mean it jerked hard but kept right on going... I thought "What the heck was that?" Well it would proceed to do this ever so often whether in OD or not, whether pulling hard or not, up or down hill it didn't seem to matter. It felt like when your pulling a hill with a heavy load and it suddenly downshifts. You know how that hard jerk feels well this feels like that only harder. It actually killed the engine several times. The first time it started when I put it in neutral and turned the ignition to start... The second time I tried that it didn't start and the motor was turning over for several minutes... I had to coast to a stop and put it in park and waited a minute or so and tried it and it started.. I proceeded to my destination with it bucking the same as before but it didn't die.

Does anyone know of this happening and know what could cause this? I think since the last time it killed the motor and it wouldn't start while still moving and in neutral that the fuel pump is the culprit. But since I don't have much experience with a diesel I'm asking for help...


Looking forward to a good answer.

 

I'd start by replacing the CPS. A cough or sputter like an intake backfire on an old gasser is a common symptom of a failing CPS.

Of course a cough or sputter is greatly magnified when you've got 20k in tow.

 

I was going to say Turbo boot but it does not look like you lost power so don't know....When mine blew off it was a big bang but no turbo psi and no power...
50" and 20,000 lbs I would like to see that, got a pic?

 

Over 70' long total... Best truck I've ever owned!

 

To clear something up though... It never made a BANG sound it just made a hell of a jolt!

 

Funny you should mention this being near St. Louis. I just got back to SoCal from a round-trip there, and had my engine do eggs-ACT-ly as you describe a number of times during the trip.

It did it several times, and each time, the tach momentarily dropped to zero, and a few times the engine died.

As Chris said above, it's your CPS. Change it, and it will stop doing that!

Reminder to self, open the glove box, use 8mm socket, etc, etc.

Pop

 

10mm socket...

Just went through my first CPS failure this a couple weeks ago. Thing is, I knew it was coming -- it would die randomly for the last several months, but I put off replacing it. Finally had to do it on the side of the road.

 

Lol. Exactly what happened to me years ago. In Michigan. In a snowstorm . . .

Uphill, both ways

 

That trailer is a monster!

 

Welcome home Pop. Sounds like you had an eventful trip. Let's meet up at Norms and I'll fill you in on truck news!

 

20K on the trailer? Hope you don't get involved in an accident, you will be in deep noonie!

 

Well the trailer is rated at over 21K so I thought I was legal...Yes - No ?

 

What does the 8 MM socket do? Oh and by the by.. nice Springer.. I had a Lab Springer mix and it was the best dog I ever had for hunting and companion... Got a full bred Lab now and he is 2.5 yrs and 150 lbs... It's a good thing I have this trailer to take him to the vet!

 

And here I've been carrying around this 8mm socket, extension, and ratchet all this time! Damn!

However, I've ALSO been carrying around a 10mm socket.

And some other sizes, too.

The socket is to remove the bolt that secures the CPS to the front of the engine.

I, too, have just been putting it off, and putting it off, as it's just kind of an occasional nuisance at this point. It DID die on me, however, going 55 in the truck lane on the long uphill grade south out of Barstow on I-15 last Wednesday. That coulda' been a safety issue if anyone was following closely.

Pop

 

One more thing to consider:

You mentioned it started to rain.

We have found that the electrical hash noise from the wiper motor can get into the CPS signal to the PCM, and create havoc.

Check and clean your grounds under the hood as below. Costs you nothing to try it.



Pop