D4C injection pump leaking internally

[3rdGenDslWrench]

Pwking I wish I could help you out a little further than this but I'm kind of at a whoa till I can get back into the shop and find some books on that engine. As far as taking the pump and the plungers out you need to Pin the pump on #1 TDC. And if you are going to remove the plungers inside of the pump when you put them back you need the Rack Centering Tool so all the plungers will put out the same amount of fuel. Now I'm not sure if the Rack center tool is the same but you should be able to take a 3/8 bolt, cut the head off and use the shoulder (no threads....the smooth part) to pin the pump on #1 TDC.

 

[reubenT]

OK; what I found today kind of helps clear up the previous mystery. Evidently the injector screens were clogging at about the same time I made the transition on the turbo. Cleaning the injectors made a big difference, now it runs on 3 cylinders quite strong. Injector no 3, which is the new one, is still not putting out enough fuel to ignite except an occasional hit, will have to do something more with it.
It also tells me the turbo pressure was giving it the extra power, not the engine oil mist it was putting out. Which I'm glad for. It doesn't have to be perfect, all I need is enough power to get some work done, and looks like we're close to having it. Even though it should run strong without the turbo. Without it when dropping it down to an idle it dies real easy, but with it it will idle slow without killing too easy.
By the way, those little forks on top the injector pump cam lifters are adjustable with lock nuts, do they adjust the amount of fuel delivered?

 

[thepumpguysc]

Do not touch the little forks!!!

 

[Old Magnet]

Those fork adjustments are used to set the timing of the injector pumps.....don't mess with them unless you are resetting/checking the timing.
Fuel control is handled by the torque spring and rack which is controlled by the governor and spring. You need to get yourself the proper manuals for the D315 engine. Rack settings are listed in the Rack Setting Manual for Caterpillar engines. There are many combinations of governor groups, springs and torque springs for various engine arrangements. Fiddling with adjustment will not obtain satisfactory results and can lead to a damaged engine.

 

[thepumpguysc]

Old M. IS EXACTLY RIGHT..
I just figured I say it in simpler terms.. DO NOT TOUCH!!
IF the lift pump is not leaking.."at a stand still" and your still getting fuel in the oil..
It {almost} has to be the pumping units itself..and seeing you replaced[cleaned] the injectors..and "the new one" isnt fireing..
My prognosis[guess] would be "that cylinder" is the problem..
You could move "that injector" to another cylinder and see if it FIRES..if so..you found your pump problem..

 

[Old Magnet]

Guess it was bound to happen....these two threads appear to have run together.....unless I missed simething the D47U is not the one with the "fuel in oil" problem.

 

[pwking13]

Yes your right OM.

3rd Gen, I don't intend to pull the the individual pumps apart, as that would do me no good, it would have to be leaking past the lifter assembly that runs against the cam. I just can't understand why all the sudden it's leaking into the oil, but I've never been that far into the pump before.