Kubota D1105 - EF07 Engine Rolling Coal at Altitude

[AaronC]

We have a couple of Kubota U-27 excavators with D1105-EF07 engines that were purchased new last year and have issues running at altitude ~10,000 ft.

We have sent them back to the dealer a couple of times now and each time they come back with "no issues found they just don't run well at altitude". They require oil changes at least every 100 hours because of the amount of soot that is deposited into the oil, and they roll coal all day long even just tracking up and down the road. The loss of power is disappointing and we are worried about what this is doing to the engine long term.

Are there any adjustments that can be made that Kubota won't allow our dealer to make on this engine? We have pulled the thinnest injector spacer on older D1105 motors to have them run a bit better at altitude, is this the same process on this motor or is the computer more involved on this newer D1105?

 

[ruffdog]

I read some articles that sounded like biodiesel is less affected by altitude. It might be something to look into.

Effect of altitude and palm oil biodiesel fuelling on the performance and combustion characteristics of a HSDI diesel engine - ScienceDirect

 

[dodge man]

A guess on my part but if the governor is calling for more fuel and the oxygen isn’t there to burn it, you get the over fueling condition. Probably just the way they are setup. If they are computer controlled in theory you could correct it but it would probably take a factory engineer to do it. It’s not like pickup trucks where they make over the counter tuners for them. If they are pure mechanical injection same thing, could be corrected but woukd take someone with a lot of knowledge on injection pumps to fix it.

 

[3Lfarms]

I take it these are not turbocharged?

 

[AaronC]

No turbocharger, supposedly Kubota is working on a kit for the machine, but that was at least 8 months ago since I last heard about that.

I'm just disappointed that these machines barely run at altitude, even down on the Front Range at 5,000 Ft above sea level they leave quite a bit to be desired. Why would any of the dealers in Colorado even sell a U27 to anyone, until they figure out how to make these excavators run at our elevation....

 

[dodge man]

10,000 feet is going to make you lose power unless you have a turbo and even then it will have some loss. My guess is the kit will just keep it from over fueling. Over fueling, to a point, won’t hurt power. If you watch truck and tractor pulls they roll coal big time, it’s not like a gas engine where to rich hurts power. If you do have a DPF that is going to cause a lot of regens.

 

[dodge man]

I just looked at the specs and it looks like a less than 25 hp engine so no DPF. If your lucky Kubotas kit will have a turbo. With a small machine without a lot of horsepower losing just a few probably impacts its ability to dig a lot.

 

[AaronC]

Yeah loosing as much power as we do hurts us pretty hard. We run our machines hard for the size they are but we also need the smaller footprint to maniver between the rocks and trees while building trails.

I wonder if they tried to get away with the smaller engine to avoid DPF, either way I think it was a bad call to not have a turbo kit ready for these guys.

This is the same motor we have in a few of our older smaller machines so it only makes sense the D1105 motor wouldn't have the power needed for almost double the machine....

 

[turbotom1052]

Besides all the soot thats going into your oil you will also probably see the oil diluted by the excess fuel. Id find someone who knows how to work the injector pump to reduce fueling. Suggest doing it in small increments until you just get rid of the black smoke.

 

[Jerry/MT]

We have a couple of Kubota U-27 excavators with D1105-EF07 engines that were purchased new last year and have issues running at altitude ~10,000 ft.

We have sent them back to the dealer a couple of times now and each time they come back with "no issues found they just don't run well at altitude". They require oil changes at least every 100 hours because of the amount of soot that is deposited into the oil, and they roll coal all day long even just tracking up and down the road. The loss of power is disappointing and we are worried about what this is doing to the engine long term.

Are there any adjustments that can be made that Kubota won't allow our dealer to make on this engine? We have pulled the thinnest injector spacer on older D1105 motors to have them run a bit better at altitude, is this the same process on this motor or is the computer more involved on this newer D1105?

You have the wrong machine for your usage! For high altitude work you need a turbocharged diesel. Your engine obviously does not have altitude compensation so it's fueling like you're at sea level or low altitude and there is simply not enough oxygen in the air charge to burn all the fuel that's being injected. You have a huge loss in power just to the effects of altitude. At 10,000 ft a 25 hp normally aspirated engine at sea level will only produce 16.6 hp under standard atmospheric conditions. While you won't gain all that back with a a turbocharger, the altitude performance will be much better.

I'd be looking at a different machine. Even adjusting the pump fuel delivery you'll still be looking at this reduction in power