2018 l2501 HST has fresh air and fuel filter ,both o rings good on fuel filter have tried the loosen fuel cap and have good fuel flow thru the fuel filter. had it at the dealer and they cant recreate the sputter so they wont work on it. it started a couple months ago and the weather temp is not part of it since its warm now and still happens
l2501 sputtering
- Thread starter chelan41
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Is there a specific load or RPM or cold vs warmed up that corresponds to it sputtering? Likewise I have a 2016 L2501 HST tractor and have experienced the "sputtering" but it usually is when I'm running back to the house at 1800 RPM or more, after a normal work period of 30 minutes to an hour.. Likewise I have loosened the cap, and no change but it will settle down if I ease back to 1600 RPM or so... I suspect a weak lift pump but don't know how to check short of switching it out for a new one?? I only have 60 hours on the tractor..
take fuel lines off of the filter (clamp them so they don't leak everywhere) and look at the inlet/outlet of the fuel filter. Clean if they have the black stuff in them. It looks like black boogers. It is algae. I like to also do a fuel flow test from the line that comes directly from the fuel tank. Restrictions in the tank are way too common.
You will have to bleed the system after doing this. There is a procedure for bleeding and it is NOT loosening the injector lines!! Your owners manual has that information.
You will have to bleed the system after doing this. There is a procedure for bleeding and it is NOT loosening the injector lines!! Your owners manual has that information.
it sputters above 1600 rpm under load and just driving it up hill in any of the gears its like no power, have to take the foot off the pedal and the engine build back power . iwe have had it in the shop for over a month and now they want to get the northwest rep involved
Took the fuel line off the filter and had good flow of around a gal/min from the open line and used a filter funnel into my 5 gal can and treated the 4 gals drained with PS Clear Diesel additive. I also checked the gravity flow thru the filter after reattaching the fuel line from the tank, and had about 1/2 the flow rate estimated.. I changed the fuel filter about 20 hours ago, but will get a couple new ones. I did make the mistake of running the tractor with the round "bleed valve" open and the tractor lost prime and died.
There was not sign of black gunk or water, but Hopefully a new filter will help.
Had a time until I pulled the rubber line off the suction side of the lift pump and got air bubbles and diesel out and finally got the tractor to run. I still have the stutters at higher than 1800 rpm at times.
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Had a buddy with a 2501 doing the same thing, ended up being a small crack in the fuel filter housing. Would pull air through there.
Im a brand new L2501 owner (7.8hours on machine) and will be following this thread closely for educational purposes. I want to encourage those affected to report back with your updates and certainly if you find the culprit for your issues as it would be very beneficial to those of us who also have new machines and could potentially run into the same issue down the line. Best of luck in getting to the bottom of it!
Interestingly the Owners Manual and the Work Shop Manual have some what different procedure for this.
Had L2501 intermittent rough running/lack of power but at times ran fine during the half dozen hours of run time since coming back from the dealer for a fuel delivery problem under warranty. They could not isolate it and were willing to come out next time it happens or could be replicated.
So Saturday decided to change fuel filter and in doing so saw the hose from filter to fuel pump hose clamp was not replaced on the outlet nipple of the filter. Okay we might be sucking air. Replaced clamp and went to bleed the injector pump and the air bleed cock was open about 3/4 turn, also not good. Did the air vent procedure in the WSM and like magic all the problems went away and it ran perfect for 3 hours after that.
WSM does not say to have the engine running when opening the air vent cock and the Owners Manual does. Tried with engine running and did not fix problem as well as ran poorly. Tried without the engine running and fixed problem. Both books say it will run poorly if air vent cock is left open.
Do you think it is just and over sight in the WSM or is the WSM correct or by experience do both methods work/are correct.
Thanks
GD
WSM does not say to have the engine running when opening the air vent cock and the Owners Manual does. Tried with engine running and did not fix problem as well as ran poorly. Tried without the engine running and fixed problem. Both books say it will run poorly if air vent cock is left open.
Do you think it is just and over sight in the WSM or is the WSM correct or by experience do both methods work/are correct.
Thanks
GD[/QUOTE]
Since the Bleed valve is located right at the injector pump block, and based on my experience when my L2501 died with the valve open, I feel that the valve should only be open for gravity flow to purge the lines, because if there is a little restriction through the filter and lines, air can be drawn back through the line from the top of the tank.
I do not have a schematic of the bleed valve, but guess that there are orings/ two positions where flow goes through to the injector pump and maybe second shunt position where flow baypasses and injector flow is off?? I guess I'll have to pull the valve stem off and look at the spindle to see? I do notice that both the filter has a auto-fill/bleed line on top with finger spring clip, as well as the finger spring clips on the Bleed Valve line. Both are attached near the top of the fuel tank. There is only about 15 inches of gravity flow head between the tank and the bleed valve depending on tank fullness..
Do you think it is just and over sight in the WSM or is the WSM correct or by experience do both methods work/are correct.
Thanks
GD[/QUOTE]
Since the Bleed valve is located right at the injector pump block, and based on my experience when my L2501 died with the valve open, I feel that the valve should only be open for gravity flow to purge the lines, because if there is a little restriction through the filter and lines, air can be drawn back through the line from the top of the tank.
I do not have a schematic of the bleed valve, but guess that there are orings/ two positions where flow goes through to the injector pump and maybe second shunt position where flow baypasses and injector flow is off?? I guess I'll have to pull the valve stem off and look at the spindle to see? I do notice that both the filter has a auto-fill/bleed line on top with finger spring clip, as well as the finger spring clips on the Bleed Valve line. Both are attached near the top of the fuel tank. There is only about 15 inches of gravity flow head between the tank and the bleed valve depending on tank fullness..
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Yep, same conclusion I had and I saw with the vent valve operation by both manuals procedures.
And, that is why I was asking lugbolt if he had seen similar examples of Kubota manuals differences and what he experienced in his daily work on these mechanical fuel delivery machines.
Thanks
GD
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The bleeder valve is just a taper set valve, no O-rings.
It has 2 states open and closed, it only opens a closes the path to the bypass hose, it does not affect open or close to the injection pump.
Thanks NIW... I will discount that valve as an area of concern and focus on making sure diesel reaches that point when I change filters next time. I pulled the fuel lift pump and noticed that when working the plunger, at one position it was closed and prevented flow thru it (just blowing on the inlet).
I also bought 2- 6mm by 16 mm cap screws to replace the hex head machine screws on the lift pump as they were a bear to get worked out..
Maybe if the engine stops with the cam at that position, it won't allow flow through it to "gravity prime" ? The last hour of operation I didnt notice any stuttering, so maybe after I get a new filter installed I'll be good.
So from following this - Seems changing the fuel filter on my L2501 may be annoying. If this is an issue with air getting in the lines, then how would you prevent that if you were to do a simple fuel filter clean/replace? Again Im following this thread as a new tractor owner who plans to do all my own routine maintenance's. Trying to soak up all the knowledge I can. Ive read of MANY instances now where someone simply replaced their fuel filter then began having engine problems and it almost always ended up being air in the line or something similar - leaving me to believe this is a common issue. How do you avoid it ?
My L3200 appears to have an identical filter set up as the 2501, never had an issue with air in system after replacing the fuel filter. There is a valve in the top of the filter housing that closes when you unscrew the filter bowl. When you screw the new filter on it pushes the valve back open and the bowl fills up. I then start it and let it idle for 30 seconds or so then run it up to about 1500 rpms for a minute and it’s good.
Just be sure to get the two o rings with the filter, they don’t come with it. There is the big one for the filter bowl and a tiny one that goes in the top center of the filter.
Ok so thats how the filter closes off. I was really curious about that, as there is no valve or switch on the 2501 like there is on the 3301. The manual mentions something about the valve closing when filter is removed but I didnt understand how that worked. I think your explanation helps me understand how that works now.
The top of the filter holds the valve open when installed, as you unscrew it the valve comes downs and seals off. It’s there just to keep all the fuel from running out of the tank while your changing the filter.
The L3301 and up have a totally different fuel system. They are common rail systems and electronically controlled. More susceptible to damage from dirt and water in the fuel.
Yea I was aware of the L2501 being different than the 3301, 3901, etc. The L2501 uses a low pressure fuel delivery system I believe while the L models beyond it use the high pressure rail system. I've read a little about the differences between the two systems. This may not be the place or time for it but I would love to read about the pro's and con's of the two systems both from a performance and operational standpoint and from a maintenance standpoint. I understand the common rail system should deliver better fuel economy and theoretically more power. I'm also curious why Kubota seems to only use the old low pressure fuel deliver system on the L2501. Is it just to get the price entry point as low as possible? I would assume the low pressure system is cheaper. Are there any benefits to the L2501's system? Just a lot of curiosities.
Without getting to far out there on this subject it’s a matter of the new emmision standards they have to meet. Your 2501 is not subject to them since it falls in the 25 hp or less. One pro to it is it’s a pretty basic and reliable system.
I was aware of the 26HP cut off for emission standard requirments. I was aware for example when shopping for my new tractor that all the L series tractors above the 2501 had the DPF systems. I guess I didn't realize the fuel delivery system was also part of that design decision. The L2501 really seems like it sits on an island all by itself in the L lineup because of this I guess.
Pretty much lol, but it isn’t that bad of an island to be on. Don’t have to worry about all the electronics and stuff on the emission tractors. Not that they have many issues but just more potential for issues.