asking for insights - Diesel Forum

oldscot44 · 11-13-2009, 08:04 PM

My vehicle: 99 F250psd. Stock except for coolant and transmission filters. Only 65,000 on the clock. Driving home today, doing about 60 mph when suddenly the truck lurched like it wanted to die. Then it picked up again. Did the same for the remaining ten miles to house at almost all speeds. Watched the rpms and they did not fluctuate. At home, drained the fuel/water filter but that did not help. Thinking about changing the fuel filter but the current one only has a couple thousand miles on it. So, until I can get a reader on it . . ... any thoughts? My initial thought was the cps which I have never had Ford replace. But with the rpms holding up I am doubtful that's it. Almost feels like a fuel feed problem. Again, ideas??? Thanks.

bigballrz · 11-13-2009, 11:13 PM

Check the wiring harness near the drivers side shock tower, it's a long shot but I had a similar problem and it was a short in the harness. The harness was rubbing in that area.

JimTJr · 11-14-2009, 07:25 AM

Do you have a CEL? If so, pull the codes before doing anything. If you have no codes I would then try the CPS. (I SELDOM recommend that as a "Fix" for anything. Some will say it's the problem for everything, LOL)
But from everything I have read on here and other forums, random misses with or without an engine code can be a symptom. Even if the Tach showed rpm. (Was it the motor going completely dead? Or did it just do a random miss?) A random miss would not show on the tach I doubt.

If it's not the CPS or if it was bucking and missing BADLY when it messed up. Then I doubt it's the CPS. (It will do a more subtle miss IMHO, I have never had one fail yet in 200,000+ miles on two Super Duty PSD's)

One of these running out of fuel, is a terrible sound/experience. I don't think anything sounds worse than a diesel starving for fuel. So if that's the case, I would check the fuel pressure. (You pump can run, (you'll hear it spinning) and still not move enough fuel to keep these running) They take a high VOLUME of fuel to keep the injectors supplied.

oldscot44 · 11-20-2009, 04:17 PM

Changed the cps - to no effect. New indication popped up - at idle it would suddenly shut off like a light switch being flipped. Got a shop to run a full diagnostic. Turns out it was the injection control pressure sensor. Swapped it out and no more codes and all's good to go. Thanks for the imputs. Unfortunately, too many things cause the same symptoms. But, everyone's experiences give places to start the diagnosis.