D2 5U stuck injector pump plungers

Has anyone had the injector pump plungers stick after sitting for a few years because of the shellac build up from the old fuel. I have a D2 that I can only turn the crankshaft about 15 degrees each way and I have checked all the gears in the timing cover, the starting penion is not ingaged, the main clutch is not stuck and I can not find anything else that would only let the crank turn about 15 degrees each way and stick. I am turning it by the fan and the compression lever is out. I pulled the fuel transfer pump apart and found it to be completly filled and stuck due to the shellac from the fuel but after I got it cleaned up the crankshaft will still only turn 15 degrees. I thought it mite be a stuck piston or hydraulic lock from water or something in a cylinder but it goes the 15 degrees very easy until it gets to the sticking points making me think that the pistons in the cylinders are free and the pump plungers in the fuel injection system may be trying to go up and down but will only go so far and then stick. It does not stick very much because you can get it to come back the other way with just a little jerk on the fan blade in the other direction. Also when it gets to a sticking point it does not make any noise like it is hitting anything. The engine only has 6300 hours on it.
I bought the tractor from someone I consider very reputable that had owned the tractor from new and he said that the diesel was runing fine when the parked it in the 70s when the pony motor broke its crankshaft and they no longer needed the tractor because that was when all the grape vinyards were being taken out of Southern California to build houses.
Also can the fuel pump barrels be taken off of the fuel pump plunger without taking the plunger out while the system is still on the engine and without messing up the rack timing.
There is a check valve between the plunger and the fuel line at the top of the barrel. is there any way to get laquer thinner past this check valve and down to the plunger to desolve the shellac. I used the laquer thinner to clean the transfer pump and it just melted it away.
Chuck

What you describe is more typical of rust in one or more cylinders.....allows some movement until you run into the rust dam that was established when water was sitting in the cylinder/s. Injection pump plungers are more likely to travel up then stick so that they don't return, same with the pump lifters. You can observe what's going on if you take the side cover off the injection pump.

Engines typically get stuck
Because the pistons are stuck
Of course that could be contaminated fuel pump
It seems to me you are looking for the wrong place

itzik

I need to know if you can remove the injector pump barrels without the pump plungers being removed and while the injector assembly is still on the tractor. I want to check that before I pull the head off the engine.

Chuck

Pump plungers should come out with the barrels, I believe without having a book handy to check.
A total of 30 degrees crankshaft movement is a rust dam in a cylinder.
My observations,
Jeff

I would bet on an intake or exhaust valve being stuck.

Perhaps you have contaminated fuel bacterium
It looks like dirt for anything
Like the leaves of Thi
But that does not cause the engine not rotating freely

I would open a valve cover
Then you can immediately identify stuck valve

You can take apart manifolds
Look for signs of rust in the engine head
Usually there will be signs of rust in two cylinders
Then insert a thin oil into the piston
And a lot of patience rotate the engine until the hard point
Return to the other side
Just do not run power

itzik

Thanks, sounds like pulling the manifolds will be the best way to keep from getting in too far. I don't want to get in so far that I have to rebuild the engine, If the pistons are stuck I will sell it and let someone else do it since it is such a low time tractor. I have to many projects to get into an engine rebuild. I have an extra pony motor and the rest of the parts that it needs that I can swap onto it to make a real nice tractor, I just don't want to do the engine.

Chuck

P.S. The tractor is a 1951 D2 Ser#4U3847 and has just over 6300 hours on it and has a Caterpillar 2A angle blade with it. If the pistons are stuck it will be for sale.
Tractor can be seen on my web site www.ferraridoctor.com

Congratulations, you guys were rite, I pulled the exhaust manifold off of the engine and I could see just a bit of rust in the nunber 2 exhaust port so I sprayed in some Kroil and left it for about 2 hours and when I turned it it went a lot further than it had been so I left it another 2 hours and when I came back it had some drag as it went thru its first full revolution and then started turning freely with just the fan blade. I had heard that they dont have to have rain get in the to rust a cylinder because if the exhaust valve is open you can get condensation in the cylinder, I had my doubts but I am now a believer.

Thanks for the help. I guess I will be going ahead with the restoration now.

Chuck