Idles down and shuts off

[19thSF]

My B2650 was running fine, when it idled down (or loaded up with diesel) and shut off. I was able to get it started in lowest idle position this AM. Drive it out of the woods, but along the way, it continued doing the same thing, except that it didn't quite shut off, and if I left it alone in lowest idle it would correct itself and I could get the RPM's back up to 2650 for a brief time., and move the tractor 100 yards or so before it happened again.

The fuel filter has about 10 Hrs on it, and there is plenty of fuel in the tank. ( Just added 2 1/2 gals, now showing 3/4 full. i use Stanadyne (spelling?) year round, and never had a problem.

The tractor has low hours (115 hours)

I am no diesel mechanic If it was a gas engine i would know where to start. SUGGESTIONS

 

[RCW]

First, as 11/11 approaches, thank you for your service, along with all other veteran OTT members.

Not very familiar with the fuel system on a B2650.

Couple background questions:

Any smoke, and what color?

Did "stumble" as it lost RPM, or did RPM just suddenly drop off?

My first thought is restricted fuel flow versus getting flooded. With an injection pump, fuel is metered to the injectors, so "flooding" is not generally typical to a diesel in most cases. There are exceptions, which I'm sure someone will point out.

There have been some issues with trash on the inlet side of the filter housing, and also sometimes the replacement/new filter is not installed correctly which causes starvation.

An algal growth can cause similar conditions.

Again, not being familiar, I would unhook the fuel line from the tank before the filter to ensure flow is good via gravity.

PS - long shot, but make sure the fuel cap vent is not plugged. Take cap off and see if it changes anything.

 

[Dave_eng]

The model of B2650 i have a WSM for describes an electronically controlled engine. There may be other models but I do not know.

I would expect some error code showing up on the dash to give you a clue of what is going on.

It sounds like the engine has reverted to a "Limp Home Mode," to protect itself.

Since you were in the woods, check closely for a wire pulled off a sensor as a starting point.

Dave

 

[19thSF]

The model of B2650 i have a WSM for describes an electronically controlled engine. There may be other models but I do not know.

I would expect some error code showing up on the dash to give you a clue of what is going on.

It sounds like the engine has reverted to a "Limp Home Mode," to protect itself.

Since you were in the woods, check closely for a wire pulled off a sensor as a starting point.

Dave

Thanks Dave,

It did occur to me to look for a pulled off wire, but I thought that I would charge up the battery and go from there. I was not even aware of Kubota "limp home mode". It is certainly true that you can learn something new every day!

 

[19thSF]

First, as 11/11 approaches, thank you for your service, along with all other veteran OTT members.

Not very familiar with the fuel system on a B2650.

Couple background questions:

Any smoke, and what color?

Did "stumble" as it lost RPM, or did RPM just suddenly drop off?

My first thought is restricted fuel flow versus getting flooded. With an injection pump, fuel is metered to the injectors, so "flooding" is not generally typical to a diesel in most cases. There are exceptions, which I'm sure someone will point out.

There have been some issues with trash on the inlet side of the filter housing, and also sometimes the replacement/new filter is not installed correctly which causes starvation.

An algal growth can cause similar conditions.

Again, not being familiar, I would unhook the fuel line from the tank before the filter to ensure flow is good via gravity.

PS - long shot, but make sure the fuel cap vent is not plugged. Take cap off and see if it changes anything.

First, as 11/11 approaches, thank you for your service, along with all other veteran OTT members.

Not very familiar with the fuel system on a B2650.

Couple background questions:

Any smoke, and what color?

Did "stumble" as it lost RPM, or did RPM just suddenly drop off?

My first thought is restricted fuel flow versus getting flooded. With an injection pump, fuel is metered to the injectors, so "flooding" is not generally typical to a diesel in most cases. There are exceptions, which I'm sure someone will point out.

There have been some issues with trash on the inlet side of the filter housing, and also sometimes the replacement/new filter is not installed correctly which causes starvation.

An algal growth can cause similar conditions.

Again, not being familiar, I would unhook the fuel line from the tank before the filter to ensure flow is good via gravity.

PS - long shot, but make sure the fuel cap vent is not plugged. Take cap off and see if it changes anything.

Thank you for your reply. I did check the fuel cap. It did not look clogged, but I gave it a good vacuuming anyway. I would say that the RPM just suddenly drops off. It is pushing out a lot of smoke when it starts. I will work through your suggestions.

Thank you!

 

[Russell King]

What color is the smoke.?

 

[Henro]

Don’t assume the fuel filter is not the issue.

When my B2910 was pretty new (less than a year old?) it started dying out, then running fine, then dying out again. I was about to have the dealer pick it up, but on a whim decided to change the fuel filter first.

That fixed the problem. Got some bad fuel apparently. Filter was so plugged I could not blow air through it (from my mouth). I could not believe the tractor could run with that filter, but it did.

I do not recall tasting diesel by the way...

 

[RCW]

The model of B2650 i have a WSM for describes an electronically controlled engine. There may be other models but I do not know.

I would expect some error code showing up on the dash to give you a clue of what is going on.

It sounds like the engine has reverted to a "Limp Home Mode," to protect itself.

Since you were in the woods, check closely for a wire pulled off a sensor as a starting point.

Dave

19thSF -

Dave is always very technically correct in his analyses.

I honestly didn’t consider an electronically controlled engine.

Doesn’t change my recommendations, but it does add another aspect to troubleshooting I did not take into account.

What color is the smoke? Just like a gasoline engine, smoke color is important.

 

[sheepfarmer]

To make it a bit more challenging, the wsm is not totally clear as to which of the electronic engine control features needed by the B3350 for regens are left on the B2650 which does not regen. They are both in the same manual. I can't presently access my B2650 wsm due to computer malfunction, to try to figure it out, but the owners manual has directions for changing or cleaning the fuel filter, it is a pleated paper element to be rinsed off in clean kerosene. That would be a safe place to start. Sometimes people describe clogs in fittings near these filters.

 

[whitetiger]

Thanks Dave,

It did occur to me to look for a pulled off wire, but I thought that I would charge up the battery and go from there. I was not even aware of Kubota "limp home mode". It is certainly true that you can learn something new every day!

The D1305-E4 engine used in the B2650 tractor is a mechanically controlled engine and does not have a "Limp Mode".
The V1505-T-E4 engine used in the B3350 tractor is an electronically controlled engine and does have a "Limp Mode".

 

[19thSF]

Thank you for your replies!
My father, a WW II vet had an expression he used when he was surprised at something that solved a problem.
He would say ............................. "well I'll be go to hell.

Per suggestion, I inspected the cap. There appeared to be a very small piece of debris in one small area, so I vacuumed it and blew out the whole cap, just in case. I don't know if the cap is vented all around or just in that one spot, but I gave the whole thing a good cleaning.

Well I just went out to the barn, and gave it a go. On the second try it started. After awhile I ran it up to 2600 RPM and ran it for 1/2 hour. Then I ran it down the side of the road, back and forth. Brought it back to the barn, shut it off and it re-started instantly like it always did. We will see what happens after it cools off, but so far so good.
The gas cap? Well I'll be go to hell!
Would the cap have caused what I experienced? Could have, if some air was getting through but not enough to prevent a vacuum in the tank. Volume out must be fully balanced by air in, or a vacuum forms, which could be relieved by a the partial air flow at very low RPM's.....maybe

If any of you are interested, I will post a "problem solved" reply tonight (provided that the problem is really solved).

 

[RCW]

Would the cap have caused what I experienced? Could have, if some air was getting through but not enough to prevent a vacuum in the tank. Volume out must be fully balanced by air in, or a vacuum forms, which could be relieved by a the partial air flow at very low RPM's.....maybe

If any of you are interested, I will post a "problem solved" reply tonight (provided that the problem is really solved).

I'm a little doubtful, but certainly hoping it was just the cap causing your problem. It really does happen, which is why I wanted to add it to my first responsive post.

As far as "If any of you are interested....", it is ALWAYS important for you to post your solution.

So many times here at OTT someone will join and immediately have a repair question. They will get several suggestions for a solution, then never report back.

We don't know if the recommendations worked, or not. If you report back, it will help the next 15 or 100 people with the same problem....

Thanks, and report back your findings.

 

[19thSF]

PROBLEM SOLVED! I would never have figured the fuel tank cap to be the problem. I usually would think of things like clogged fuel filter, failed fuel pump, fuel line blockage. But .................................... I went out after the tractor had fully cooled down and it started up immediately as it always did, and ran fine.

So, lesson learned, when faced with many choices or explanations the simplest one will usually be correct. That's Occam's razor for anyone into medieval monks who said smart stuff.

 

[RCW]

PROBLEM SOLVED! I would never have figured the fuel tank cap to be the problem. I usually would think of things like clogged fuel filter, failed fuel pump, fuel line blockage. But .................................... I went out after the tractor had fully cooled down and it started up immediately as it always did, and ran fine.

So, lesson learned, when faced with many choices or explanations the simplest one will usually be correct. That's Occam's razor for anyone into medieval monks who said smart stuff.

Well I'll be go to hell.....

Woo Hoo!!

Glad I added the "PS" - Check the fuel cap.

My grandfather wasn't a medieval monk nor well-read, but was a pretty decent farmer self-taught mechanic.

He always said start with the simple stuff...

Sincerely hoping all stays good, if not the other recommendations still hold true.

Best wishes!!

 

[armylifer]

I am glad that your problem was solved so easily. I would like to mention one more thing that can cause the problem as you described. My next door neighbor changed the fuel filters on his BX 2350 and after changing them his symptoms were near like what you described. He asked me for help and I found that he installed one of his fuel filters backwards. I took the filter off and reversed it, and the engine started to run correctly again. The moral of this story is that if you accidentally install one or both of the filters backward, you may not get full fuel flow and therefore no power.

 

[19thSF]

I am glad that your problem was solved so easily. I would like to mention one more thing that can cause the problem as you described. My next door neighbor changed the fuel filters on his BX 2350 and after changing them his symptoms were near like what you described. He asked me for help and I found that he installed one of his fuel filters backwards. I took the filter off and reversed it, and the engine started to run correctly again. The moral of this story is that if you accidentally install one or both of the filters backward, you may not get full fuel flow and therefore no power.

Thanks "armylifer" "Airborne all the way". I certainly can see how a reversed filter restricting fuel flow might cause the same symptoms. Who would think to look for that when having an issue, this is, until now. I would like to tie this chain of posts to "engine shuts down or goes to a rough very slow idle". It might say people a lot of trouble with two "keep it simple fixes". I'll have to figure out how to do that.

 

[armylifer]

Thanks "armylifer" "Airborne all the way". I certainly can see how a reversed filter restricting fuel flow might cause the same symptoms. Who would think to look for that when having an issue, this is, until now. I would like to tie this chain of posts to "engine shuts down or goes to a rough very slow idle". It might say people a lot of trouble with two "keep it simple fixes". I'll have to figure out how to do that.

Actually, it was not that difficult to find the problem once I found out what he did. He told me that the problem came up after changing the fuel filters. I crawled under his tractor and looked at that filter, looked under the hood and saw that it was oriented differently than the one under the tractor. Neither filter had a marking for the correct orientation so I looked at mine and figured out which orientation was correct and changed the wrong one to the correct orientation. Worked like magic.

 

[sheepfarmer]

Thanks "armylifer" "Airborne all the way". I certainly can see how a reversed filter restricting fuel flow might cause the same symptoms. Who would think to look for that when having an issue, this is, until now. I would like to tie this chain of posts to "engine shuts down or goes to a rough very slow idle". It might say people a lot of trouble with two "keep it simple fixes". I'll have to figure out how to do that.

That is a good idea, but be sure to add the caveat that they should check and understand that the different Kubota models have wildly different fuel filters. The best place to look is the owners manual. If a poster includes a picture of their fuel filter orfuel cap folks will realize that yours looks nothing like theirs.