Oil & Fuel Kubota BX2360 choking up in the cold

[ruger.john]

It seems like it is freezing up which it has done before. The dealer has had it several times and blamed the fuel freezing up. Took off the tank blew out the lines replaced the filters and fuel pump and put in new fuel. Worked for a few hours a day or so ago but temperature today was below zero and it only worked for 30 minutes when it had all the same symptoms and just made it back to the shed(un-heated). Waited a while and it started up and ran fine. Filters did not look frozen up. We are adding the additive recommended by the Kubota dealer. I am beginning to think it is not the fuel. Any feedback?? Thanks

 

[jbrumberg]

Welcome to TBN. When the tractor starts lugging" is there any exhaust smoke? and if so what color?

 

[dodge man]

There are some threads on here about adding a fuel filter setup from a B series Kubota or a Racor system. The stock filters on a BX suck. Mine froze and/or plugged up twice. Even with the Racor on mine and a fuel additive, mine gelled up this winter. The advantage of the Racor is it has a clear bowl and you can see the gelling.

 

[RjCorazza]

If it ran for 30 minutes, limped to an unheated garage, then after a while parked it ran fine I doubt you have a fuel gelling problem.
My ZD mowers use the same electric fuel pump and inline filters. The ZD’s will somewhat run (intermittently) with a bad pump, and the first filter can clog fast causing fuel starvation. Even if the pump or filter are not your current problem, consider dodge man’s advice on replacing the first inline filter with something better. My ZD’s both have large 2 micron spin on filters, and non-oem electric pumps (Mr. Gasket diesel pumps).

 

[BeezFun]

If you just cleaned the tank and lines, I'd leave the filter element out and see if the problem goes away.

 

[Peter 315]

If you leave the filter off you might ruin the injector pump:2cents:

 

[dodge man]

Do not leave the filters off. Below zero temp the fuel probably gelled in the filters.

 

[fishpick]

@ruger.john - you said you are running fuel with "adding the additive recommended by the kubota dealer" - what are the additives?
What's the temp - you say cold but that's relative... my friends in South Florida consider 50F "freezing"
Is the diesel you replaced the tank with "new" or "old" - I see you are in Quebec so I assume like here in NY there's a summer blend and a winter blend up there...
Just looking for a few more details!

 

[Egon]

Fuel gelling & plugging filter.

When warmed sits in shop in the shop engine heat melts gelled filter and let's you start again.

 

[JWR]

If it ran for 30 minutes, limped to an unheated garage, then after a while parked it ran fine I doubt you have a fuel gelling problem.
....

I disagree completely. I assume you meant "below zero" as below zero F and more than 17 below Centigrade ? If YES, continue reading what I am about to say. If NO forget my comments here. The symptoms you describe are typical of diesel fuel gelling. Not actually "freezing." It is guaranteed to happen at zero F and I have seen it at about 11 deg F. with an automotive diesel. The warmth from running it a short time, being inside a closed place no matter heated or not, probably loosened up the fuel flow. This fits perfectly with a case where you had added an additive recommended by the dealer (!) and you were right on the edge of more serious gelling. It is also a perfect illustration of why I claim that additives are only a marginal solution that help in a limited way and DO NOT fix the problem with any certainty. Additives are just a maybe of a fix. Most of us do not want a Maybe. I have said in many posts that the real and certain fix is to mix #1 fuel (kerosene) with your normal diesel #2 fuel in a 50-50 mix. I repeat one more time, this is exactly what the heavy equipment operators do in northern VT and NH and places with climates similar to yours. In the very cold weather, just run half kerosene. It will hurt absolutely nothing. The lube qualities are only slightly degraded and that for a relatively short time. Your power output will be reduced by a tiny % and you will NEVER notice either of those 2 side effects. By the way, your experiment essentially shows how much the additive lowered your gelling point (or rather how far it did NOT lower the gelling point.) Lowered it some, just not enough. The additives won't hurt anything but if you really want a reliable solution, mix in the kerosene. I do not have the numbers but ask your local heavy equipment operators -- they can tell you how far below zero F the 50-50 mix will cover you.
By the way, there is no reason at all to get into these messy (and potentially problem causing) screwing with filters. Once the engine is warmed up running on a usable mix of fuel for a while the gel will be "disolved" in the various filters. Only if it was so bad you could not get it to run at all would screwing with filters be warranted. Even then it would be better to just move it to a warm place for a few hours. Good luck and let us know how this all came out.