Kubota D1105T 3 cylinder engine, too much fuel

[tfleming]

Hi guys, hope someone can assist here. I have a Kubota D1105T engine on a Toro commercial mower. Bought it used and not running. so, after a wee bit of normal "pre-start" checking, found no fuel getting to the injectors. Ok, so I pulled the injector pump and cleaned a boat load of gum out of it (pistons were stuck in the "up" position). Re-assembled the pump, and now getting good fuel. She started right up, and made enough black smoke to fill the shop in under a minute.

Next, pulled the injectors and cleaned them. Re-installed, and same result. Had injectors spray and pop tested. Junk. Installed "new" rebuilt injectors. Fired her up again, still black smoke, but not nearly as bad.

So, these 3 injector cylinder pumps do not have a fuel adjustment on them. Smoke is black, not white/blue. Engine has a moderate detonation knock at lower RPM's which goes away at operating speed.

Now, I am at a loss. The turbo is working just fine, intake manifold is wide open and clear of obstructions. Why I am getting too much fuel? It looks like I am hooked to a pulling sled at a truck pull with the pump turned all the way up.

Thoughts? Suggestions? I am trying to avoid taking a 2nd mortgage out on the house to have a diesel shop look at it (which I am willing to do if I have to).

PS: only took the pump body out, so no timing changes for anything I have done.

 

[greenacresnorth]

does it just sit that and smoke idleing or only when you rev it up? fuel knock is normal at idle, its kinda a rattle noise because of indirect injection.

 

[tfleming]

I smokes at idle and at full throttle. Knock goes away at full throttle. The new injectors helped, but did not totally resolve the issue. I would estimate it reduced the smoke by 50%. One thing I am going to check today is the valve lash. This thing sat for at least 5 years without running, and not in a heated building. If the valves were stuck or sticky, and it bent the push rods, it could be that the intake valves are not opening all the way. If that is the case, it would be starving for air. I am going to check that today. I am NOT a certified diesel mechanic (old school gasser guy), but I understand enough that this thing is either a.) getting too much fuel, or b.) starving for air. I just for the life of me can't figure out why...............

 

[kuboman]

I'm betting you still have gum sticking up the injection pump.

 

[tfleming]

I'm betting you still have gum sticking up the injection pump.

ok, i'll bite on that. So, wouldn't that produce the opposite effect: not enough fuel? Not arguing, just trying to determine cause and effect in your suggestion. If the injector pump is still "sticky" it shouldn't pump the correct amount of fuel. This thing smokes like a stoked up coal boiler! LOL.

absolutely willing to take the pump apart again...............

 

[North Idaho Wolfman]

Sounds like you didn't time the pumps in the injection pump correctly, and yes it's different that timing the engine.
I would have to see the pump, to tell you how to do it, Kubota has used several models over the years.

 

[100 td]

but I understand enough that this thing is either a.) getting too much fuel, or b.) starving for air. I just for the life of me can't figure out why...............

One can remove air cleaner/air intake to be sure for air starving but more than likely pump issue as you have noted.
Does the pump have adjustable delivery valves on the top of the pump?

 

[greenacresnorth]

I smokes at idle and at full throttle. Knock goes away at full throttle. The new injectors helped, but did not totally resolve the issue. I would estimate it reduced the smoke by 50%. One thing I am going to check today is the valve lash. This thing sat for at least 5 years without running, and not in a heated building. If the valves were stuck or sticky, and it bent the push rods, it could be that the intake valves are not opening all the way. If that is the case, it would be starving for air. I am going to check that today. I am NOT a certified diesel mechanic (old school gasser guy), but I understand enough that this thing is either a.) getting too much fuel, or b.) starving for air. I just for the life of me can't figure out why...............

if its smoking all the time i would be willing to bet one of the delivery valves are advanced beyond the other 2 causing it to fuel knock and smoke. there is a linkage called a fuel rack that ties the 3 DV and piston assemblies together, there are timed and trimmed to "balance" fuel to the 3 injectors, an out of balance pump will cause hard knock and dark black smoke. that fact that you had pump apart adds fuel to this theory.

 

[Luckystars]

Have the pump cleaned and calibrated.

 

[tfleming]

Thanks for the comments guys. I will tell you that the pump went back together exactly as it was disassembled. I kept each piston assembly together, so shims were not mixed up when reassembled. Also, the pump housing was not removed from the engine, only the pump body, pump cam shaft was never touched. If it is out of time, it was that way before I started (unless there is something I am missing about the pump body). The slide rack can go on only 1 way, and each piston also has a slot, there is only 1 orientation that the pistons can go into the cylinder sleeves.

Again, I am not a diesel expert, but the pump was disassembled, cleaned, and reassembled as it came apart, keeping each pump piston, shim, spring, and cylinder matched. Could be the pump is junk as well. From what I can gather from the manual, there is no adjustment to these pumps except to change the shims size.

 

[North Idaho Wolfman]

Thanks for the comments guys. I will tell you that the pump went back together exactly as it was disassembled. I kept each piston assembly together, so shims were not mixed up when reassembled. Also, the pump housing was not removed from the engine, only the pump body, pump cam shaft was never touched. If it is out of time, it was that way before I started (unless there is something I am missing about the pump body). The slide rack can go on only 1 way, and each piston also has a slot, there is only 1 orientation that the pistons can go into the cylinder sleeves.

Again, I am not a diesel expert, but the pump was disassembled, cleaned, and reassembled as it came apart, keeping each pump piston, shim, spring, and cylinder matched. Could be the pump is junk as well. From what I can gather from the manual, there is no adjustment to these pumps except to change the shims size.

Did you pull the rack out?
Did the pump have 2 screws on each of the pumps?
Also if the seal is bad it will also cause it to not pump correctly.
I'm not saying you have or have not done it right, but I've rebuild quite a few pumps and I've see a lot of them, that were put together wrong.

 

[tfleming]

wolfman, yes, I had to take the rack off as it was stuck and gummed up as well. Yes, there were 6 screws on the rack retention plate. I am the first to admit, that I may have re-assembled this thing wrong. I did NOT take the top off of the pump. pistons #2 and #3 were stuck in the "up" position. I also noticed that each piston had to go back into the cylinder in a specific orientation, with the slot to the rear of the pump. They would not go in any other way. Now, if that is a travel limit on the piston itself, then I DID re-assemble it incorrectly, because those puppies when oriented with the slot to the rear, will go full stroke. if not oriented that way, they will only go a partial stroke. If that is the case, I would assume that the pistons are over stroking then. That could be the problem. The way the control face is machined on the piston (plunger in the manual), there are only 2 orientations. Slot to the rear, or slot to the front. I have the slot to the rear. I can certainly take it back out, and rotate 180 degrees. However, the piston will not go full travel at that point. Maybe that is the problem, as there is a stroke limit on these, and since it is going full stroke, it is making too much pressure (fuel). Manual says that this is a Bosch MD type mini pump.

 

[100 td]

Check your messages

 

[North Idaho Wolfman]

Ok, if you pulled the rack you most likely have gotten it out of time.
The timing marks are on the rack and on the pump gears, and they can only be seen and lined up when you pull the pump and look into the bottom.
I'm quite surprised that you did what you did without pulling the pump out of the engine.
You can pull the pump without changing the engine timing or any other ill effects.
Does the pump have 2 screws per pump outlet on the top of the pump?
And if it it did take out the pumps and did not put the plates back on exactly as they came off it's also out of time because of it.
My best suggestion would be to pull the pump take a bunch of pictures, post them and we'll see if we can get it straitened out for you, I've done quite a few of them.
Worst case scenario is your going to need to have the pump professionally rebuilt.

 

[robdean]

I have the same issue. What was the solution?