Kubota rough running and smoking

[BIGSKYSNOWBLOWER]

I have 3240HSTC and operate around 7500 ft elevation primarily with snowblower running off the mid PTO. I have had the tractor about 18 months and have put just over 200 hours on it. At idle and low rpms it seems to run fine. Under the load of the snowblower at 2800 rpm the engine runs rough, produces blue smoke and the smell of raw diesel. I have changed the air filter and fuel filter which did not seem to make much difference. I have also run some Power Service through it although it was not the injector cleaner per se. Any thoughts and what might be going on?

 

[Willl]

My very first thought was air cleaner, but you've changed it so that's out.

Rats nest in the intake snorkel ?

 

[Chessie]

Hello,

Does it also do those symptoms when it is unloaded and run at high RPM's??

Is it possible powdered snow or some other type of debris has managed to accumulate someplace that is ultimately restricting airflow before the air cleaner.

Are you allowing enough warm up time for the engine?? before you really load it up the temp gauge should be up off of the "C" a little bit

I assume that you have winterized the fuel since you are up that high. could be poor fuel. try adding a little kerosene to thin out the fuel a little. check fuel filter bowl to make sure it is "clear" and not foggy looking.

One other issue could be that at that altitude you may have to consider de-rating the engine horsepower a little bit as unless the engine is turbo charged it will be "over fueling" for the amount of air available to provide proper clean combustion. try running at 2200 max RPM and see if that eases up on the running faults. It may simply not be getting enough oxygen that high up.

hope this helps.

Jeff

 

[638]

It's the altitude. The injection system has no way to tell the amount of air entering the cylinders. It needs more air or less fuel. Since you are not able to pack more air into the cylinders, you need to reduce the amount of fuel that is injected. I don't know how to do that, but your local dealer should be able to tell you or do it for you. Perhaps one of our forum members can help out here.

 

[razor]

When you say you replaced the air filter. I'm guessing that the L3240 has a primary and a secondary filter and both replaced?

 

[BIGSKYSNOWBLOWER]

As to the air filter, someone asked if I had replaced both elements, which I did. As to the high rpm, it runs rough at high rpm whether or not it is under a load. As to fuel, I have been using #1 dyed diesel. When I first got the tractor I used #2 dyed diesel and it smoked significantly more (black smoke) than after I changed to #1.

I suspect those who blame the altitude are right, but early on it never ran rough, just smoked a lot. That leaves me wondering if I might have a bad injector or two. I will talk with the dealer about adjusting for high altitude.

Thanks for all of your input. Would love to hear any other thoughts you might have.

 

[Chessie]

Hello,
Couple of things. you might try to see if the timing is right on the fuel pump (dealer unless you have the technical service manual) It may be able to be adjusted slightly to ease up on the smoke a little.

since it does it with clean filters and #1 fuel then pretty much you are dealing with starving for air. This is only going to be fixed by turbo charging the engine which would be really expensive. Its just the nature of the beast unfortunately.
Jeff

 

[jerrykn]

I've got an L35 I picked up a couple months ago. I am at 7000 elevation and only get a little smoke when under a heavy load, never any roughness, almost 1200 hrs on the Bota. I picked it up in No Carolina were it ran well also.
Can't imagine 500 feet would make any difference.
sounds like poor timing or low fuel pressure to the injectors.

Good luck

Jerry

 

[tdev]

Did you by any chance accidentally mix some gasoline in with your diesel? I have seen this happen several times, to check ,smell in your fuel tank. Also have you used starting fluid on some cold day? If you use to much it can blow the top of the pistons off. Good luck.

 

[copperhead1967]

Could it be a faulty glow plug or wiring or firing? Is it possbile to not notice it as much until your increasing the RPMs and are dumping more diesel into the cylinders? If the diesel isn't burning, its going out the hot exhaust in the form of smoke and smelling alot worse. . I'm not much on diesel engines but know a gasoline engine will run like crap if only 5 of the 6 plugs are firing, the more you pour in the fuel the worse it will complain. Seems like a similar comparison.