B2910 - Puff of Smoke

[QueBota]

There was a similar post on the JD forum a while ago. I get a small puff of smoke when I accelerate from idle to approx. 1800 rpm or above. It seems to be more blue than black or white. Only happens if you move the handle quickly, if you run it up gradually it doesn't smoke.

Air filter looks good, still running the factory oil at about 34 hours. It may have done this from day one, perhaps the thread on the JD forum made me more aware of this. I know my truck smokes more when the temps and humidity are up.

Thanks,
Dave

 

[deminin]

I saw your post yesterday, and today, after doing some work on my loader, I tried my 2910 under quick acceleration. I moved the throttle quickly several times, and did not notice any smoke. The only smoke I get is a small black puff at initial startup. I have about 280 hours on my rig.
If you are still running the factory oil/filter, you might want to change it. I changed my oil/filter at 30 hours, 65 hours, and 100 hours, before I went into the recommended 50 hour cycle. All engines will seat in, and there will be minor metal shavings, etc., created during this process. I like to get that out before it causes any scuffing of the cylinders, bearings, etc. Oil and filters are a lot cheaper than overhauls. I use only WIX oil filters...I think #51344 is the correct one for the 2910...and Shell Rotella T 15W40 oil. This is the combination that all the local farmers use in their hi dollar rigs, so thats good enough for me. I don't know who makes the Kubota filters, but I do know of the excellent reputation that WIX has.
If this persists, and it concerns you, you may want to have the dealer check the fuel pressure, and/or injector pump adjustments....or just increase the RPM's gradually if the tractor seems to be running well. Jerking the throttle might be just creating a momentary flooding that is causing the smoke.

 

[techman]

What you are seeing is completely normal for a diesel. Due to the way the governor works in the injection pump, when you make a fast speed change on the throttle, the injection pump quickly delivers a much greater quantity of fuel into the cylinders. It actually exceeds what the engine can handle, since it takes a bit of time for the RPMs to wind up. During this time the engine goes rich and you are seeing unburned or incompletely burned fuel. As soon as the engine RPMs pick up the fuel level is reduced and the excess fuel is not being injected.

In diesel cars, the concern for polution and the much smarter computer based engine controls meter the fuel to the injectors at a more progressive rate, eliminating the rich running condition.

You will see this characteristic in nearly all off road, heavy construction and industrial diesels.

paul