1994 6.5 Diesel. Very harsh fuel Cutoff
 

I started a thread a few months back with this truck not running and would surge on acceleration and misfire. I put in different injectors, cleaned the tank, replaced the fuel sock in the tank, cleaned out the entire fuel system, and replaced the PMD and relocated it.

It ran fine for about 1400miles before having any problems.

Now it is not possible to hold the engine at any given RPM above idle because it just goes all the way to redline if you touch the pedal at all.
While driving for the first 15 minutes, the rpm hangs at 1900 when I shift (manual trans) and does not go down.

Speeds up to 55 on a level surface, you can slow down without hitting fuel cutoff. Anything above 55 and the sucker will continue to accelerate until I let off until it goes into fuel cutoff.
What really bothers me is when I have to accelerate again and when it fires it is very harsh. One hell of a shock to the trans and differential.

I am getting Code 35 and 36 which is Fuel pulse width too long and Fuel pulse width too short.

The truck runs great, lots of power and no stumble.

I have no idea what is causing this.

it almost sounds like a pmd problem

I thought that too, as soon as it started doing it, I switched to another PMD that worked before and it did not change. After that failed, I checked the computer it is good and has no internal circuit faults.

What gets me is that it waited nearly 1400 miles before doing anything.
If all else fails I am going to shotgun the injectors, fuel cutoff solenoid, then move to the throttle actuator.

I just saw oil in the inlet of my turbo and in the intake so I guess the CDR valve is shot, so I am guessing this could cause some wonderful issues with lets say injectors. I am not too sure the MAP sensor likes oil either.


How do you like those Duratherm Glowplugs? Mine are about due to be replaced and I wanted to put something nice in it.

there nice glowplugs and there self regulating so if you ever to extend the glowplug time with a switch they wont burn out too fast. i wonder if your pedal is going out

I think you have something there.

Right before it started acting up on me it threw code 84 and 99 one time. They never came back after I cleared it so I did not think anything of it. It has never come up with the "check throttle" light though.

84 is "Accelerator Pedal Position (APP) Circuit Fault"
99 is "Accelerator Pedal Position (APP) 2.5 Volt Reference Fault"

Well. I guess it is time to throw some money at that. I am not spending $400 on a new one though. :ouch:

Well. It is not the pedal or the cutoff solenoid.

I need to find a wiring diagram for this thing.