Fuel Starved Engine

[Stickbo]

I have a Kubota MX5100 and yesterday it started acting up on me while doing some disking. After running fine to begin with, it suddenly started stuttering and lost power, nearly killing the engine until I disengaged the clutch. I barely limped back home. I took out the fuel filter and found a fair amount of black crud in the separator bowl. I didn't have a new filter on hand so just cleaned the existing one and reinstalled. It ran fine for awhile again, then started the stalling and losing power act. I cleaned the filter once again, and then it ran fine for the next 2 hours or so. Once again, it suddenly lost power. This time I noticed that it happened immediately after I ran across a very bumpy stretch, and I wondered whether I had broken lose some sort of crud again in the fuel tank.

When I got back to the barn I left the tractor running and noticed that the separator bowl was only about half full. After a minute or so of idling the bowl filled completely again. Now I am wondering further if there is an obstruction somewhere in the fuel delivery line and/or in the tank itself. That separator bowl should be completely full, correct? If fuel is not flowing properly that could sure cause my problems.

I am going to pick up a couple of new fuel filters tomorrow. My plan is to remove the filter and bowl and try to drain the tank as far as I can. (Fuel level is less than 1/4 tank now) I'll replace the filter, and see what happens. My only problem is that I only have another hour or so of field work left to do this fall, so it may be awhile before I get a chance to run it for many hours. I won't really know for sure if the problem is permanently fixed.

Any other thoughts or things I should try?

 

[Junkyard Jim]

I'm not familiar with that particular system but it sounds like you probably had the diesal "fungus" that grows in tanks and some of it has broken loose. Have you recently switched to a hotter fuel or put in an additive? You will need to flush the tank and lines eventually if that is what it is. I usually take the line off at the sediment bowl and aim it into a clean container with several layers of cheesecloth to filter out the thick stuff and keep refilling the tank with the filtered fuel until it comes out clean. You can add a little air pressure at the fill if it needs it. A full tank of fuel with an additive if you aren't going to use it for a while and a new filter and away you go.

If you are really worried about if it fixed it or not, go back and disc something you already disced if you just want to run it.

Good luck with it

 

[Stickbo]

I just bought the tractor used last spring. (It only had 180 hours on it at the time)
Not sure what the previous owner ran, but a station I have bought from sells "Biodiesel". In my research on this problem I fits read something about an algae of some type that can form and that Biodiesel can kill it. Could be the problem? ?
I'll be trying your suggestions. But do hope I can get by without removing the tank. That looks like it could be quite a job.
Thanks!

 

[Junkyard Jim]

What you are calling "algae" is what I'm calling "fungus" for sure. It's in most diesal tanks and doesn't cause much of a problem until you kill it one way or another. The more you can slosh the fuel around in the tank the better. There may be some after market additive that will help break it up, but I've just done the filtering method and it seems to work.

When the Army switched from DF2 to JP8, we went through **** trying to keep stuff running. It will eventually all filter out.

 

[Stickbo]

It sure sounds like that could be my problem. The only thing that makes me wonder a bit is that the crud I found in the sediment bowl seemed more like flakes. What I read about the fungus or algae is that is kind of slimy? But I will definitely be trying the tank flush.
Thanks again!

 

[MNBobcat]

I've seen many a fuel filter that is only half or a quarter full and the engine runs fine. I suspect the separator doesn't need to be full to run properly.

I would start by replacing the filter. Then you could pick up some diesel additives that boost the cetane level and also removes water. It wouldn't hurt to try it.

 

[eray1066]

Last monthI had a similar problem with our Kubota L4150. It would occasionally starve for fuel with the filter bowl going empty. You could blow into the tube attached to the filter that vents the filter. You could hear air bubbles in the tank. Then it would run for a while. My brother and I drained the fuel and removed the tank. We tried to look inside but the fuel gauge is on the opposite end of the tank than the outlet so no view. We shook the tank got out a bunch of black gunk we replaced the tank thinking we were done. Nope. So i used a hole saw to make an access above the other end of the tank and we were able to get a good view. There was apiece of plastic in the bottom of the tank. It was just waiting to block the outlet again We removed the plastic and more gunk with a grabber. Sealed up the tank and it is all good. Plastic was probably in a fuel can spout

 

[Stimw]

While you are looking at things check the fuel cap to make sure the vent is working.

 

[kbutabob]

What I have seen is usually theres a 90 degree nipple on fuel filter head that will stop up as the fuel is entering filter head. You can either run a wire in it or air blow it out, PS (there is still trash in tank! )

 

[Tx Jim]

What you are calling "algae" is what I'm calling "fungus" for sure. It's in most diesal tanks and doesn't cause much of a problem until you kill it one way or another. The more you can slosh the fuel around in the tank the better.

True Algae grows in a fuel tank when water is present. When it gets bad enough to begin plugging filters it can be a real PITA. Fuel conditioner with Biocide or formaldehyde will kill it