Kubota L3410 (D1703) Won't Rev high, white smoke

[CobraTom]

So I have a strange case for you experts.
I have a L3410 with a D1703.
I purchased the tractor with a motor that was run low on oil and as a result broke the camshaft and bent a rod.

I finally found a replacement motor after a year of searching that was intended to go into a air compressor before the next level emissions got implemented, as a result it got shelved and I purchased it NOS.

The motor required a lot of parts to be removed for a tractor application, outside of the obvious (Intake manifold, exhaust manifold, oil pan, oil pickup) I also had to swap over the front cover to line up the water pump and the oil filter.

As a result of having to swap these (the throttle levers and governors are different) I had to remove and swap over the governor and linkage as well as springs, etc.


Tractor starts up fine with a lot of white smoke and diesel fuel smell. Glow plugs work fine (Get voltage, and have proper resistance.

Fuel has been changed out, filter has been cleaned. Tried it with a electric fuel pump same thing, swapped injection pump with the older unit from the other motor and same effect. At no point was timing touched.


Its clearly getting over fueled and the timing seems strange.I thought it was possible one of the injectors was dribbling and stuck open, but I removed the exhaust manifold and all 3 cylinders do the same thing.

Is it possible the rings are not seated yet?


Here is a video:
https://youtu.be/7hp8CY9VXvM

 

[D2Cat]

Engine sounds fine. I'd adjust the valves to make sure they are set correct. Be sure coolant level doesn't change, and use the tractor.

Use an infarad thermometer to check temperatures at various engine and radiator locations to be satisfied things are not overheating.

 

[CobraTom]

Engine sounds fine. I'd adjust the valves to make sure they are set correct. Be sure coolant level doesn't change, and use the tractor.

Use an infarad thermometer to check temperatures at various engine and radiator locations to be satisfied things are not overheating.

I agree that it does sound fine until it hits 2300rpm or so. The issue is it will not even rev to proper PTO speed.

Coolant is fine. I even pressure tested the coolant system and all is well on that front. It is definitely a fuelling issue.

 

[North Idaho Wolfman]

I would like to see / hear a video of it starting.
To me it sounds / looks like injector issue.
Maybe bad injectors.
If the fuel cam shaft was out of the GEN / Air compressor motor, then it could be that the lift and duration of the cam is limiting the fuel.
Could also be caused by a maladjustment of the valves.
Did you verify that the injection pump timing (adjusted by shims) is right?

 

[JerryMT]

So I have a strange case for you experts.
I have a L3410 with a D1703.
I purchased the tractor with a motor that was run low on oil and as a result broke the camshaft and bent a rod.

I finally found a replacement motor after a year of searching that was intended to go into a air compressor before the next level emissions got implemented, as a result it got shelved and I purchased it NOS.

The motor required a lot of parts to be removed for a tractor application, outside of the obvious (Intake manifold, exhaust manifold, oil pan, oil pickup) I also had to swap over the front cover to line up the water pump and the oil filter.

As a result of having to swap these (the throttle levers and governors are different) I had to remove and swap over the governor and linkage as well as springs, etc.


Tractor starts up fine with a lot of white smoke and diesel fuel smell. Glow plugs work fine (Get voltage, and have proper resistance.

Fuel has been changed out, filter has been cleaned. Tried it with a electric fuel pump same thing, swapped injection pump with the older unit from the other motor and same effect. At no point was timing touched.


Its clearly getting over fueled and the timing seems strange.I thought it was possible one of the injectors was dribbling and stuck open, but I removed the exhaust manifold and all 3 cylinders do the same thing.

Is it possible the rings are not seated yet?


Here is a video:
https://youtu.be/7hp8CY9VXvM

White smoke indicates unburned fuel. Have you checked the air filter and induction system? Is the valve timing and valve size the same between the two engines? Smaller valves could limit air flow. Is there white smoke across the whole range of operation?

Generators and compressors generally run near constant speed slowing down a little as load increases. Tractor engines generally run across the full range of allowable rpm.

The problem could be in the injector pump and/or the injector capacity.A You really need to get information on the hardware differences between the two types of engines to be able to find the source of your problem. It may be as simple as a mod to the injector pump and/or different injectors or it may required changes in a multitude of components.

 

[CobraTom]

First off. Thank you! You guys are awesome. The intelligence of the responses I have received so far took me from being very frustrated to seeing a glimmer of hope. It was very black and white to me before, and I really appreciate you guys introducing factors that I did not think about. I will quote each post with a response so its easier to read.

 

[CobraTom]

I would like to see / hear a video of it starting.
To me it sounds / looks like injector issue.
Maybe bad injectors.
If the fuel cam shaft was out of the GEN / Air compressor motor, then it could be that the lift and duration of the cam is limiting the fuel.
Could also be caused by a maladjustment of the valves.
Did you verify that the injection pump timing (adjusted by shims) is right?

I 100% concur in thinking that its a type of injection issue.
I thought it could be a injector issues as well seeing how the motor sat for so long un run. I took one injector out and took the unit apart and it was essentially new. There was no carbon build up, rust or anything and since all 3 were doing it I naturally assumed (I will post a video of the unit running a constant higher RPM and having each cylinder release a bit of smoke at different times.

At that point I removed the injection pump that came with the new motor and replaced it with the one off the old motor, they share the same Zensol/Bosch part number and had the same amount of shims.

I did not think about the fuel cam being a different shaft and limiting the motor RPM in this manner. However if the fuel is limited it would not give me overfueling at max RPM, it would give me underfueling (which is what essentially controls the RPM in diesels anyways...

As for the valves, that was something on my list, but figured it would present itself throughout the RPM range and not just at at max RPM?

Here is another video of the constant RPM. I will get one of it starting. It involves alot of smoke.

https://www.youtube.com/watch?v=CQMtTAWdVJU

 

[CobraTom]

White smoke indicates unburned fuel. Have you checked the air filter and induction system? Is the valve timing and valve size the same between the two engines? Smaller valves could limit air flow. Is there white smoke across the whole range of operation?

Generators and compressors generally run near constant speed slowing down a little as load increases. Tractor engines generally run across the full range of allowable rpm.

The problem could be in the injector pump and/or the injector capacity.A You really need to get information on the hardware differences between the two types of engines to be able to find the source of your problem. It may be as simple as a mod to the injector pump and/or different injectors or it may required changes in a multitude of components.

The motors are identical other than their Tier emissions. The head casting and the block casting as well as the part number for the injection pump and the injectors are all the same. The newer industrial motor vs tractor design had a difference with the front timing cover and placement of stop solenoid and throttle control. The water pump impeller sits lower as well so I would not be able to use my radiator fan extension piece like these tractors require. The oil filter also sits too low and would cause it to be behind the frame rail of the tractor. These are the only reasons behind changing the front cover.

I would take the change of the front cover out of the equation altogether as I am confident the motor would run the exact same way with its original timing cover.

BTW. Tried running it briefly without a filter, made no difference.

 

[North Idaho Wolfman]

After watching the second video, I would say valves are too tight.
If it was over fueling it it would be blowing black smoke, the white/ blue smoke Looks more like bad burn, either too early or too late or fuel is being cut off to early.

Also it could still be a fuel cam issue, a fuel cam for an emission engine will have either a lower lobe height or shorter duration, as it will limit the amount of fuel delivered.
If you have the other engine there compare the fuel cam shafts.

 

[CobraTom]

After watching the second video, I would say valves are too tight.
If it was over fueling it it would be blowing black smoke, the white/ blue smoke Looks more like bad burn, either too early or too late or fuel is being cut off to early.

Also it could still be a fuel cam issue, a fuel cam for an emission engine will have either a lower lobe height or shorter duration, as it will limit the amount of fuel delivered.
If you have the other engine there compare the fuel cam shafts.

Isn't Black Smoke = Too much Fuel/inefficient Burn
White Smoke = Too much Fuel, Fuel is not igniting?

The issue with the fuel camshafts, it would not explain the mid rpm and bad start, as the air compressor profile/emission profile would still have to run at those RPM.

 

[Tooljunkie]

Checking valve lash/pump timing is free....

 

[CobraTom]

Checking valve lash/pump timing is free....

I intend on checking valve lash, but how exactly should I be checking fuel pump timing?

 

[lugbolt]

Do a compression test. Take no one's word as to whether it's new or not, unless you see it come out of a Kubota crate, from a Kubota warehouse or dealer. You're looking for around 500 psi give or take a little. That's the first step.

Injection timing will cause a knock if it's too far advanced, and low power/smoke if it's retarded-and high EGT's either way if it's severe, enough to melt pistons. Usually if it's timing related, it'll do it at all RPM and worse under load even at lower RPM.

Since you replaced the engine, do you have the old injectors to try them to eliminate that possibility?

Air starvation issue sound plausible. If it were me working on it (and it's obviously not), I'd remove the air intake and run it, the hose to the filter. Actually it's possible to just remove the intake manifold and run it. Eliminates all possibilities with the intake system.

Look at the easy stuff first. Then dig deeper. Being that it's not a tractor-specific engine, and of an unknown history, you may have some loops to jump through.

 

[CobraTom]

Do a compression test. Take no one's word as to whether it's new or not, unless you see it come out of a Kubota crate, from a Kubota warehouse or dealer. You're looking for around 500 psi give or take a little. That's the first step.

Injection timing will cause a knock if it's too far advanced, and low power/smoke if it's retarded-and high EGT's either way if it's severe, enough to melt pistons. Usually if it's timing related, it'll do it at all RPM and worse under load even at lower RPM.

Since you replaced the engine, do you have the old injectors to try them to eliminate that possibility?

Air starvation issue sound plausible. If it were me working on it (and it's obviously not), I'd remove the air intake and run it, the hose to the filter. Actually it's possible to just remove the intake manifold and run it. Eliminates all possibilities with the intake system.

Look at the easy stuff first. Then dig deeper. Being that it's not a tractor-specific engine, and of an unknown history, you may have some loops to jump through.

It is definitely a new motor. It was in crate with original kubota covers on the intake, exhaust and injector pump.
Like I mentioned before, I have run it without any of the air hose parts with the same effect. I have seen air starvation and it usually presents itself in black exhaust smoke.

I do have the old injectors and I will throw them in if adjusting valves does not make a difference.

 

[MadMax31]

You wanna roll coal, not roll snow. White smoke is usually raw fuel. Definitely check valves, timing of pump would be last resort, Ive read they can be a handful.

 

[1810]

I appreciate the wealth of feedback already provided but I have one question...
If you have the original injection pump installed, with its shims....if you disconnect the outlet pipes (at the top of the injection pump...going to the injectors)....what do you see when the engine is cranked?
From each outlet on the pump, you should see a sequential "spurt" / small quantity of diesel ejected as the camshaft turns and causes fuel to be ejected to each cylinder in rotation. So, the question is this....do you see any difference between the 3 outlets from the injection pump when you crank the engine?

 

[CobraTom]

I appreciate the wealth of feedback already provided but I have one question...
If you have the original injection pump installed, with its shims....if you disconnect the outlet pipes (at the top of the injection pump...going to the injectors)....what do you see when the engine is cranked?
From each outlet on the pump, you should see a sequential "spurt" / small quantity of diesel ejected as the camshaft turns and causes fuel to be ejected to each cylinder in rotation. So, the question is this....do you see any difference between the 3 outlets from the injection pump when you crank the engine?

No difference in any of the ports. Had the injectors out of the head and attached to the pump and all squirted as they should.

Frustrating. It appears the valve lash is right on the money as well.

 

[100 td]

NIW may be on the money with the fuel camshaft being different, it's possible that it's tuned for exact emissions at 1800rpm full load if setup for a genset, or compressor if it has the same rpm spec. You could ring Kubota Industrial and get a part number for the shaft and compare to tractor shaft number.

However my thoughts would be with something wrong with the governor/springs setup, restricting full opening of the fuel rack as you have been unable to achieve full rpm with no load.

Depending on what rpm the other governor is set for, it still needs to output fuel for full load at it's set rpm, so lets say it is set for 1800 rpm, you would still be able to load the engine to maximum load at that rpm, and should see some black smoke when initially putting that load on the engine as the pump opens to max fuel.
If you do try the compressor governor again, load the engine up at the set rpm and see how it goes.

Is it possible that you accidentally stretched a spring when removing or reinstalling the tractor engine governor?
Have you adjusted the max rpm stop?
EDIT: Just found this info on a D1503: Be careful not to stretch the small governor spring too long
because otherwise it may be deformed permanently.

 

[100 td]

Does your new engine have one of these here, I expect it's max rpm set screw, but happy to be proven incorrect. There will be a plastic cover over the set screw. Be careful adjusting it as you don't want to have your engine over revving, also it will only come into play if everything else is set correctly, so if you adjust and get no increase, then fix the trouble with the governor/pump and/or springs etc, the engine may then over rev due to the adjustment being incorrect as it had never reached the set screw stop previously.

 

[CobraTom]

I have not touched this engine since last year after this discussion, It has been parked since then and I am just looking at working on it now.

I don't think anything is wrong with the fuel cam or governor springs or anything like this.

I am producing a heavy amount of white smoke at high rpm, which suggests over fueling.

I am starting to lean towards stuck rings, I will do a compression test today to see where it stands.