Linstrum
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Equipment
L3400HST with BH76 backhoe, L2501HST, B7100HST, B7100DT, all with fel's. Cat D4D
L2501 HST with a little over 100 hours, all service performed according to the book - everything was done, nothing was skipped, and everything used was from the Kubota dealer. Tractor was ordered in October or November of 2022, and delivered to dealer in December, 2022. It is stored indoors in a locked garage. Fuel is kept indoors and purchased from a truck stop with high sales volume, no "farm fuel" or biodiesel used.
I already read the L2501 thread started by chelan41 on April 21, 2019, where those symptoms are not the same.
After normal operating for several minutes, or well over an hour, under good load doing work like pulling the box scraper that is almost full, or running the rear-mounted mower in tall weeds that make the engine work, when the engine is idled-down, it idles perfectly. No misfiring at all. After a few minutes, when the throttle is opened up to go back to work, the engine immediately starts to misfire on all cylinders, and almost stops running for maybe 15 seconds. Sometimes there are a few puffs of white smoke, but otherwise the exhaust is clear. After about 15 seconds of misfiring, the engine picks up and runs normally again with total throttle response, as it should be.
The misfiring happens every time after letting the engine idle for a few minutes, maybe a bit longer. As already stated above, the engine idles without any misfiring or even a hint of misfiring, but as soon as the throttle lever is pulled back to increase engine rpm, the misfiring begins and the engine almost stops running, with rpm dropping very low. After about 15 seconds, sometimes longer, the misfiring ends, and the engine begins running normally and the rpm picks up according to throttle position. Once the misfiring is over and the engine once again is running normally, the engine delivers full power and the tractor will operate the box scraper about half full of dirt for 100 yards down the shoulder of the road, or continue mowing weeds. From that, I doubt very much that it is a plugged fuel filter or other lack of fuel problem. The Kubota dealer insisted it was a plugged fuel filter, but the evidence is firmly against that, since the engine delivers full power that requires adequate fuel.
So, what is going on with all these mysterious problems with L2501 engines not running right? My tractor runs great under load at high rpm when fuel consumption is highest, its problem is it runs great at idle rpm but almost dies WHEN the throttle is opened up to increase rpm from idle. This problem showed up after the engine was broken-in enough to start working the tractor with a good load on it. So, the problem may have been there all along, but didn't appear until the engine could be worked with a good load on it.
I already read the L2501 thread started by chelan41 on April 21, 2019, where those symptoms are not the same.
After normal operating for several minutes, or well over an hour, under good load doing work like pulling the box scraper that is almost full, or running the rear-mounted mower in tall weeds that make the engine work, when the engine is idled-down, it idles perfectly. No misfiring at all. After a few minutes, when the throttle is opened up to go back to work, the engine immediately starts to misfire on all cylinders, and almost stops running for maybe 15 seconds. Sometimes there are a few puffs of white smoke, but otherwise the exhaust is clear. After about 15 seconds of misfiring, the engine picks up and runs normally again with total throttle response, as it should be.
The misfiring happens every time after letting the engine idle for a few minutes, maybe a bit longer. As already stated above, the engine idles without any misfiring or even a hint of misfiring, but as soon as the throttle lever is pulled back to increase engine rpm, the misfiring begins and the engine almost stops running, with rpm dropping very low. After about 15 seconds, sometimes longer, the misfiring ends, and the engine begins running normally and the rpm picks up according to throttle position. Once the misfiring is over and the engine once again is running normally, the engine delivers full power and the tractor will operate the box scraper about half full of dirt for 100 yards down the shoulder of the road, or continue mowing weeds. From that, I doubt very much that it is a plugged fuel filter or other lack of fuel problem. The Kubota dealer insisted it was a plugged fuel filter, but the evidence is firmly against that, since the engine delivers full power that requires adequate fuel.
So, what is going on with all these mysterious problems with L2501 engines not running right? My tractor runs great under load at high rpm when fuel consumption is highest, its problem is it runs great at idle rpm but almost dies WHEN the throttle is opened up to increase rpm from idle. This problem showed up after the engine was broken-in enough to start working the tractor with a good load on it. So, the problem may have been there all along, but didn't appear until the engine could be worked with a good load on it.
