Engine sputtering...What's going on?

[cp1969]

Mmmmmmm......I don't think so. I've had a fair amount of experience with water in diesel fuel systems and I don't ever remember one sputtering or missing on account of water in the system. Water in the bottom of the filters won't restrict anything.

Restricted fuel filters result in decreased power, but not missing or sputtering.

 

[kmdigital]

Maybe it was water. While you seem to think that is the preferred solution, it is the very last thing I would want it to be! Almost anything in a diesel is better than water in the fuel, as can very quickly damage both the injectors and the pump. Furthermore, most diesels have water traps in the fuel filters to prevent the water from getting into the pump and injectors, where they wreak havoc. Usually, you won't get water in the pump and injectors until the fuel filter is pretty much completely full of water, as water is heavier than #2 fuel oil. Anyway, it seems to be better, it's your tractor and you're happy with it.

 

[RobJ]

Its a relative thing. Filters are made to flow from outside to inside. This tends to close the pleating during flow. A filter that has become somewhat plugged by debris or by absorbing water finally reaches a critical pressure difference across it that willclose the pleats. At that point the lurking problem becomes real real fast.
larry

I can go along with that, but man that's got to be far along, the whole pleat design in filters is to not allow blockage or lose performance as the forgein material builds up. Shame on Mr. Operator.

 

[RobJ]

Maybe it was water. While you seem to think that is the preferred solution, it is the very last thing I would want it to be! Almost anything in a diesel is better than water in the fuel, as can very quickly damage both the injectors and the pump. Furthermore, most diesels have water traps in the fuel filters to prevent the water from getting into the pump and injectors, where they wreak havoc. Usually, you won't get water in the pump and injectors until the fuel filter is pretty much completely full of water, as water is heavier than #2 fuel oil. Anyway, it seems to be better, it's your tractor and you're happy with it.

You know you can always yank a filter, even a new one, and dump it on the ground and see what's inside, then reinstall. Heck half of my fun is seeing what's inside!!

And a fuel filter on each side of the transfer pump, never seen that, usually in a 2 filter set up there is a primary and secondary back to back. I could see a problem with air if there is anything other than a solid line going from the tank to the transfer pump.

Good Luck,
Rob

 

[Lockport]

OK. How it could simply resolve itself without any intervention and go from this to running perfectly normal if it were anything but water that worked its way out requires an explanation. I just can't see it unless there is a piece of cellophane or something floating around in the tank but it was like that for two weeks and then suddenly cleared itself up. Seems kind of unlikely.

 

[Soundguy]

If it was water, then if any de-watring chemical adds were added to the fuel, it might have taken them time to do their work.

2 adds come to mind.. emulsifiers.. and solvators. If it was a solvating kind.. there is a max amount of water it can hold in soloution.. as fuel passed the trapped water inthe filter it solvated until the soloution was saturated.. and kept going... after enough treated fuel passed the 'wet' filter to solvate all the water out.. 'boom'.. problem gone.

Just a WAG.. but at least it is a 'possible' explanation..

( solvating type dewaterers are personally not my prefered method in a desiel engine.. etc.. )

soundguy

 

[RobJ]

Oh wow cool video man, that says it all for sure. Sounded like mine with air in it though. Sounds like you checked everything and now it's working...leave it alone.

But with a lift pump on your engine I'd say the fuel is circulated throught the injector/pump retunr line to the tank and a good rate. So if you put in some water stuff it should have mixed up good and run through the system.

But if my tractor did that it would also drive me crazy!!

Good Luck,
Rob

 

[SPYDERLK]

I can go along with that, but man that's got to be far along, the whole pleat design in filters is to not allow blockage or lose performance as the forgein material builds up. Shame on Mr. Operator.

The L series uses filters several times bigger that the filters in the BXs. They are extremely trouble free due to their large surface area per HP engine served. The tiny BX filters [and perhaps weak pump] are more highly taxed and are extremely touchy to non optimum conditions. Water is the absolute worst. Consider waters softening effect on paper in addition to its pore blocking effect. I have both series tractors. Theres no comparison between the coddling one must be given over the other.

larry​

 

[cp1969]

Water does not readily dissolve into diesel fuel; it naturally separates out and because water weighs 8.3 lb/gal and diesel weighs 7.2, water settles to the bottom of any container or low spot of a fuel system. Diesel fuel can hold a small amount of water in emulsion but not nearly enough to cause the engine to miss (more on this later). Diesel engines do not respond to water in the fuel like a gas engine does. The gas engine has a very narrow range of fuel:air ratios in which the engine will run. A small amount of water can upset that mixture and cause a miss. The diesel operates over a much wider range of mixtures and is not affected the same way.

A diesel injection pump delivers the same fuel to each injector. If enough water was to get to the fuel injection pump then all cylinders would get the same dose of water and ALL cylinders would miss. The engine would cease to run. In other words, the fuel injection pump cannot deliver a 'bad' load of fuel to one cylinder without delivering it to all of them.

I bought a truck once that must have had 10 gallons of water in its fuel tank. The previous owner must have NEVER drained the fuel water separator. Every day we would drain anywhere from a pint to a quart or more of water out of the water separator. It took at least a month but we finally got it all out (good thing, too, as winter was approaching) but the truck never hiccuped once during that period when it had to be running on the maximum amount of emulsified water possible.

That's why I don't think water was the cause of your miss. Air, on the other hand, will cause a miss. That is just about the only thing than will cause a diesel engine to miss. If a bubble of air comes up to the injection pump, it will try to inject it into a cylinder. I've had some experience with that, too, but it usually manifests itself as a no-start situation. The smallest of air leaks can cause the system to lose its prime while sitting, thus no start. Mechanical problems can cause a miss, too, i.e. injector problems.

 

[RobJ]

The L series uses filters several times bigger that the filters in the BXs. They are extremely trouble free due to their large surface area per HP engine served. The tiny BX filters [and perhaps weak pump] are more highly taxed and are extremely touchy to non optimum conditions. Water is the absolute worst. Consider waters softening effect on paper in addition to its pore blocking effect. I have both series tractors. Theres no comparison between the coddling one must be given over the other.

larry​

Larry, for grins after you comment I googled the Bx fuel filter. Now the clamp comment makes sense. I had no idea that Kubot sort of cheaped out on the filter by using a simple in-line clamp on filter. The filter on my L is(was, see the Racor on now) a spin on (still sort of small, maybe 3x3). If the BX filter is sitting on it's side or near side, water will collect there and could probably been seen.

I'm gonna have to stick with air on this one. I agree with a lot of what cp1960 stated.

Rob