L3430 Blocked Fuel Pick Up Causing Stalling

[Fxfymn]

I haven't been on the board for awhile, but I thought I'd pass along what happened to my 3430.

While plowing snow last winter the tractor lost power and stalled out due to a lack of fuel. Since it was pretty cold I assumed the fuel had jelled so I added anti-gel, blew the line out and it seemed to be fine.

Than about two weeks ago I was taking the tractor to a friends house when the same thing happened. It acted as if it had run out of fuel, and when I primed it it ran for a short time and than quit again. After a couple of re-primes it ran long enough to make it to my friend's house where we used compressed air to blow out the intake line. After blowing it out the fuel flow greatly increased so it was obvious something had blocked the fuel pick up in the tank.

I ran it long enough to basically drain the tank with the intention of removing the tank to try to find the obstruction. But when I started lookling at it, I realized that taking the tank off was probably going to be an all day job, so I removed the sending unit to try to see any item that might be blocking the pick up.

I was able to get a light into the fuel fill so I could see inside the tank. There was enough fuel left to block my view of the tank's bottom, so I stuffed a rag into the tank to sop up the remaining fuel. After I pulled the rag out I found the remains of several insects in the tank.:thumbsup:Since a couple of these were pretty large I assume they were being drawn into the fuel hose inlet and blocking it enough to limit fuel flow. I used a flexible pick up tool to grab the bugs and remove them from the tank.

My guess is the bugs got into the tank from my farm tank that is equipped with an open nozzle. After this experience I put a piece of screen across the nozzle outlet.

So, a couple of lessons learned; the fuel tank does not have any kind of screen or sock in it to screen out debris, bugs will not disolve in diesel fuel, and if you have an old fashioned farm tank with an open nozzle put a screen across it to keep the critters out.

 

[JoeL4330]

I had the same experience with my L4330...in my case I was able to suck the obstruction through the fuel line, before my filter. I did learn--as did you--that an emergency short term fix is to disconnect the line at the filter input and blow back up into the tank (don't swallow).

In my case, too, insects seem to like the inside of the fuel nozzle and I have a cover I can slip over my spout...this doodad works for my nozzle (3) NO SPILL 0206 6" FLEX EXTENSION GAS CAN SPOUT NOZZLES on eBay!

The other (neat) thing I do, because I have a filter in the line before the nozzle is to put the first bit of fuel back into the "server" tank so, if anything was in the nozzle it is now in the server tank and will (eventually) get filtered out. You might try this...A screen would have to be awfully fine mesh to do the job.

 

[Don87]

I ran into the same problem with my old Cub Cadet. Spiders, flies, and other insects in my fuel tank.
Some of the insects made it into the fuel filter.

I use 5 gallon cans.

 

[David_Kb7uns]

Got these to keep the dirt out of the toy hauler fuel station nozzle, they work well.


New RV, Toy Hauler onboard fuel station nozzle cover | eBay

David Kb7uns

 

[kuboman]

Oh this sounds so familiar. This is the reason I keep a small rag stuffed in the nozzle and a bucket beside the bulk tank and run a small amount of fuel into the bucket each time to flush the 'foreign' material out.:thumbsup:

 

[Fxfymn]

I keep the tank locked, so running fuel back into it is not an easy option, but it is a good idea.

Love the sock idea. I am going to order one for my truck mounted tank.

Window screen works fine given the size of what you are trying to keep out. My fuel fill hose has a filter on it too, that hopefully, will keep the fine stuff from the tank out. If fine material makes it to the tractor the in-line filter should get it.

What surprises me the most is that Kubota designed the fuel pick up to come from the dead bottom of the tank without any kind of screen. That means that it is inevitable that any debris, water, etc. that gets in the tank will be introduced into the fuel system.

 

[Willl]

I use,,, (let me rephrase, it got loaned out),,, I had a 'Mr. Funnel'.

Best filter funnel out there.

Mr Funnel

Shurhold

(Shurhold/Mr Funnel same thing/company)

 

[JoeL4330]

FXFYMN: That's what I thought initially, but it is that design that allows you to actually purge the tank completely without removing it, which is a major project...and, the fuel filter prior to the injection pump is designed to, well, filter. If there is a design mistake, IMHO, it is that the fuel line is not sufficiently larger than the tank opening so things can (and do) get caught in the line, prior to the filter ...for which the first aid is: blow back.

The other trick I have used (on my Jetta TDI to get the prime back) is to use the outlet of my shop vac to mildly pressurize the fuel tank ...which forces fuel through the line with more authority than the gravity feed of the design. In the case of the Jetta, it brought fuel from the tank to the fuel filter without having to try and pull a vacuum all that way. For the L4330, it cleaned out the fuel line quite nicely.

 

[Fxfymn]

I don't disagree, but if they had engineered a simple 1" upturn in the discharge it would have eliminated the need to purge the tank since most of the crap would simply settle below the intake. Or, they could have used a very large discharge outlet and placed the filter right at the tank discharge. If the goal is to make the tank totally drainable put a cone shaped screen on the tank side of the discharge so an item cannot enter the hose.

I had assumed the stoppage was my fault for failing to keep the debris out of the tank, but since others have had the same issue it's apparent that the design is questionable as well.

To me if you use a design that will allow the tractor to quit while it is being used, when a better design is cheap and doable, than you are failing as an engineer.

 

[JoeL4330]

Well, there's always room for improvement. Not being able to fully purge the tank means you can't (easily) get to any water, which will settle to the bottom and should be caught by the filter, no? Putting the filter immediately adjacent to the tank solves one problem, but putting it as close to the injector pump might solve another ...tradeoffs ..and, in our case, at the tank outlet would make it harder to see and to change, no? As for making the outlet larger (good idea) there still will always be a restriction in any line ...the question is, where do you want it ...I would like it to be at the filter, myself. I like/liked the filter design with the float bowl (at the lowest point, note) that would capture/show water and heavy solids.