I posted awhile back about my surging throttle/power loss problem. I followed the advice given with regard to freeing up the fuel pin in the afc. It looked a little sticky, and now is nice and free . Unfortunately the problem is unchanged.

It will rev up to a certain point, bog down and then surge up/go down with the throttle being held in the same position.(some missing as well) I'm going to check on the shutdown solenoid, maybe the connection is bad, but after this I'm stumped.

I don't think it's the injector pump as there is no smoking in accordance with the problem, and I don't know about it being the injectors, because once it starts to go it goes with full power, no missing.

The problem is really bad when it's cold outside, initially really bad, and still present even when the truck has warmed. it's also bad when trying to go up a hill.

A question I thought of when working on the afc was about the little solenoid that appears to turn a little black thing in the bracket that goes right over the afc housing. This little thing was extremely stiff, and I don't see how that little thing could turn that. What is this thing, and could it be the problem?

This thing is frustrating

Any help would be greatly appreciated, as I am learning my way along working on diesels.

 

Do you think this problem could be my kdp? Some guy I talked to mentioned this. What does it look/sound like when the kdp is going bad? I know it gets expensive if it blows though.

 

it is definitely not the kdp making your power fluctuate

 

The "little black thing" is the TPS, that lets the computer know how far you are pushing the accelerator down.


It sounds like a fuel supply problem to me. Have you changed the fuel filter recently? How old is the lift pump?

 

Yeah -- I would buy a tapped banjo bolt from Genos Garage and put a fuel guage on the line after the fuel filter. If you are getting good fuel pressure to the injector pump, and your shut-down solenoid isn't flaking out, then your governor is sticking. The shaft that the fly-weights spin on can wear, and cause similar symtoms.

This is not too common, however, and would only make sense if the pump were quite worn.

 

The fuel filter was changed a couple of weeks ago, and the lift pump is under a year old. I wonder if it wasn't a dud?

Should the thing under the tps be very stiff to turn/does it turn?It seems to have a small quarter circle it should turn it, but is so stiff I can't turn it by hand. Any possibility that this is the problem?

I would think the injector pump is o.k. Only 325k kilometers on it. As well it roars with full power throughout different parts of the throttle range.

How do I check, and or fix a sticky governor?

I really appreciate the responses guys, this ones a puzzler, and I don't have the cash to get someone else to do it right now.

Also, if I gear down the truck, it will usually go to full power, but not when cold. Cruising at 100 km/hr is stutters, cruising at 105+runs just fine.

 

Alec,

Can you tell me a little more about the governor sticking and the fly-weights. Do you mean full throttle (pedal to the floor) may not always mean full throttle inside the pump?

Brian

 

You wrote "KDP" did you mean "KSB", the cold start ?

 

I'm having this same sort of problem, and of course I'm worried about the fuel issues, with my Waste Veggie Oil, but I've also had what I thought was a lot of TPS problems... can anyone confirm that this sort of fluctuation (I seem to have it at 35mph and at 55mph... as though it's trying to shift back and forth from 3rd to 4th) ... and the engine *sounds* the same.. that is, there's no loss of "firing" or rev, just the power.

Tys

 

Just because your engine doesnt smoke, or because it has ONLY 320Km, doesnt mean in itself that it is still good. I've had them be bad and need rebuilt but still not smoke, with only 150K mi. Trucks that get used (within reasonable limits) tend to last longer than cream puffs- those that never work.

If your fuel supply checks out good, I'd say you have some internal pump issues or could need injectors.

Daniel