Strange Behavior After Draining Fuel Tank Because Of Water [VIDEO]

[Lobanz]

OK. So my L3400's fuel tank probably got some water in it from my fuel drum. I always use a water separating filter funnel and this is why I noticed it but I think the funnel filter has a leak in it and let some water through. The tractor has never done anything except start and run perfectly and has less than 500 hours on it. I keep the maintenance up and all. The following happened over about 3 days.

So I immediately drained the tank and the fuel filter bowl. (Well I did turn on the engine for less than a minute before draining the tank so I could move the tractor about 10 feet away to a spot I could work on it). Filled filter bowl up with clean diesel and bled via the banjo valve on injector pump. I went to mowing and noticed after a while that it was bogging down. RPMs dropping, losing power, running a little rough and making a little white smoke. So I bled again at the injectors. Seemed to help, but then I mowed for another hour and it happened again. Was running fine, but suddenly noticed that it was dragging again.

So I replaced the fuel filter and bled the lines. Seemed to run perfectly again and mowed for about an hour and it started bogging down and running rough again. So I drained the tank AGAIN and filled with fresh diesel. Problem still happened after 45 min to an hour of mowing.

So, when I bought the filter I noticed that there were supposed to be two o-rings, one big and one tiny. I didn't remember seeing the tiny one, so I bought one and put it in the little hole on the top of the filter element and reinstalled. Bled lines. Worked wonderfully and thought that fixed it.

I left it idling while I put the loader back on and unhooked and swept off the finish mower. I tried running the engine at full throttle and the problem surfaced again. Could not sustain more than about 2000 RPMs. Was making a little white smoke. Acted like it was starved for fuel. After idling a little bit longer the symptoms went away and it would sustain high RPM with no smoking or anything. Problem came and went in about 10 minutes.

Here is a 1 min video of it in its unhappy state:

It doesn't seem to be air in the lines. Those are thoroughly bled to the injector pump and at the injectors. There is likely no water at all in the fuel given that I have drained the tank TWICE. There are no fuel additives in the fuel. I never remember seeing the little o-ring though. It wasn't stuck to the housing and I don't remember it being on the filter element -- just the large one. I wonder if it got sucked up in the fuel line and into the IP or something. It just seems like it's not getting enough fuel to run at higher RPMs. Not sure this explains the little bit of white smoke though.

I don't really want to take it to a shop because they won't be able to reproduce it and will still charge me $400 or something.

I'm at a loss as to what's going on. I figure I'll just keep an eye on it and see what happens.

Any ideas?


--- Lobanz

 

[Egon]

When you drained the fuel tank did you look inside to see if it was empty?

Check your fuel drum for water.

 

[Lobanz]

No, I did not look inside the fuel tank when I emptied it. No gunk came out. Just clean looking fuel. Not even sure that any water actually made it to my fuel filter.

Yup. There is water in the fuel drum. That's what caused the whole thing. Gonna put a Goldenrod water block filter and particulate filter after my GPI hand pump. Also want to put a Racor separator on the tractor (see THIS thread).


--- Lobanz

 

[Wagtail]

Although I can't suggest anything that you haven't done already, I'll relate an experience of mine. The short story is that a 'late evening' top-off (half tank) of diesel turned out to be diesel smelling water! The tractor died in the field. I drained the tank (overnight) and went home after letting the people who topped me up what had happened.

The next day, having bought a new fuel filter, we changed the filter & filled the tank with fresh diesel (that I bought), bled the injectors and the tractor fired up just fine.

As I was moving on to the next paddock via a connecting public road (revs @ 2400, High, 2WD) the tractor suddenly lost power and belched significant white smoke. Scared the h3ll out of me! :shocked: The tractor recovered and it didn't happen again. So, the symptoms suggest that the engine was getting rid of a 'glob' of water.

Cautionary note: 4 years later, due to assuming that all of the 'diesel smelling water' had drained, I had to contend with a debilitating biological growth in my fuel tank. So, add some biocide treatment to your tank. Even if you've cleaned it you might not have gotten rid of it all.

 

[Lobanz]

[...]As I was moving on to the next paddock via a connecting public road (revs @ 2400, High, 2WD) the tractor suddenly lost power and belched significant white smoke. Scared the h3ll out of me! :shocked: The tractor recovered and it didn't happen again. So, the symptoms suggest that the engine was getting rid of a 'glob' of water.[...]

Yeah. Maybe it just needs some time to work through it. Doesn't "feel" like it, but I hope that's all it is. I want to replace the existing fuel filter with a Racor 120 AS water separate / filter.

[...]Cautionary note: 4 years later, due to assuming that all of the 'diesel smelling water' had drained, I had to contend with a debilitating biological growth in my fuel tank. So, add some biocide treatment to your tank. Even if you've cleaned it you might not have gotten rid of it all.

I do use PRI-D and PRI-Ocide in my fuel drums. Hopefully that helps.

Thanks for the response! It seems like your experience is how it's supposed to work. I hope mine is just working through little bits of water.


--- Lobanz

 

[3Lfarms]

The symptoms sounds just like a fuel tank not venting properly. Next time it happens, leave it running and remove the filler cap. See if sucks in air and then starts running better.

 

[Lobanz]

Good call, but no dice. I already tried it. Doesn't make a difference. I'll try it again, though.

I don't see any holes in the fuel cap. Not sure how it vents.

 

[Dave M7040]

Your tractor, according to Messick's part diagram, has a mechanical lift pump to feed the injector pump is this correct?

When trying to solve intermittent problems. I like to bypass components and then see how the machine runs.

You are suspecting water related problems, have drained your tank but to no success.

Get a squeeze type bottle, perhaps a mustard container and a piece of rubber hose.

This link will show you what I mean

Vollrath 12 Oz Yellow Plastic Squeeze Bottle - 2 1/4"Dia x 8"H

Connect the squeeze bottle directly to the injection pump intake, bleed the system and then try running the tractor while holding the squeeze bottle to supply fuel to the engine.

If it runs great then you are on the road to success. If it does not then at least you wont waste more time on the fuel system.

Dave M7040

 

[Lobanz]

Tractor seems to be running perfectly, but I haven't run it for an extended period. No problems maintaining high rpms. No white smoke or power loss We'll see if the problem is still there next time I mow. Previously, I had to run it 45 min to an hour before the problem occurred. Because of this, I agree with 3Lfarms that it sounds like a vacuum building up in the fuel tank because of a lack of venting.

Still looking at replacing existing fuel filter a Racor filter. Just need to make a new mounting bracket for it. Doesn't look like the bigger filter would be much more vulnerable in that position. I'll probably add a fuel shutoff valve as well to make changing the fuel filter easier.

 

[Lobanz]

Update. I noticed the power loss again after just idling for a while. Was just moving some stuff around with loader. Nothing big. But it idled long enough to get good and warm. Just increased the RPMs to about 2000 and pressed the hydrostat pedal forward. Noticed it being laggy and not wanting to keep a steady RPM. Uncapped fuel tank. Didn't help. Didn't hear vacuum hissing from cap. Looks to happen only when engine is warm enough. Doesn't seem to correspond to load.