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

[CobyRupert]

Sounds like venting problem, which you've eliminated.
Guessing in the dark here:
Is fuel line metal all the way? I've heard of rubber hoses that get soft and kink/collapse, but only when warm.

 

[Lobanz]

It's rubber hose all the way, but never had an issue prior to draining tank after I suspected water got in it. I'm clueless, but it really bothers me because it has never given me a minutes trouble. And I'm afraid to take it to the dealer because they probably won't take the time to reproduce it.

 

[Gary Fowler]

I think I would put a new fuel hose on it from tank to injection pump (any thing that is rubber). Not a big expense and will eliminate a bad hose section as the culprit. If you have metal sections, blow them put good when replacing the hose. If you have no fuel shut off valve at the tank, now would be a good time to install that also.

 

[Mauser12]

I had the same type of thing happen with only 10 hours on a new tractor. I suspected water and did just about as you did. Nothing seemed to help much but the issue went away in a day or two. I still believe it was water but have no proof.

 

[Lobanz]

Well, that's good to know, Mauser.

Mowed a little yesterday. Problem manifested itself after about 45 minutes of mowing. Power loss, won't hold higher RPMs. Bogs under very little load. Doesn't run as steady. Makes a little white smoke.

I had been loosening the fuel cap and retightening it ever so often -- bout every 10-15 min I guess. So I don't think it's vacuum. Tank is almost empty.

I let it cool down some (bout 25 min) and the problem was less severe but still there. So I think it's heat related.

Can rubber hoses weird out and constrict the fuel when they warm up?

Anything else anyone can think of anything that might make these symptoms that are heat related? Worked fine before I drained the tank. Really seems like fuel starvation.

Could it be the fuel pump? Maybe water in the fuel damaged it?


--- Lobanz

 

[Dave M7040]

Well, that's good to know, Mauser.

Mowed a little yesterday. Problem manifested itself after about 45 minutes of mowing. Power loss, won't hold higher RPMs. Bogs under very little load. Doesn't run as steady. Makes a little white smoke.

I had been loosening the fuel cap and retightening it ever so often -- bout every 10-15 min I guess. So I don't think it's vacuum. Tank is almost empty.

I let it cool down some (bout 25 min) and the problem was less severe but still there. So I think it's heat related.

Can rubber hoses weird out and constrict the fuel when they warm up?

Anything else anyone can think of anything that might make these symptoms that are heat related? Worked fine before I drained the tank. Really seems like fuel starvation.

Could it be the fuel pump? Maybe water in the fuel damaged it?


--- Lobanz

Sometimes it is a good idea to bypass a lot of the fuel system when you are having problems like you are. The typical trick is to get a squeeze bottle like on for mustard ( which I cannot stand) and fill the squeeze bottle with good diesel.

Arrange the fuel inlet to the injection pump so you can easily disconnect the normal line and connect your squeeze bottle with a long hose so you can sit in the drivers seat while squeezing the bottle to supply fuel. Other variations on this theme are possible such a a gas can and an electric pump all connected temporarily. Doing this will soon confirm if you have a fuel supply issue or something else even a restriction is the exhaust system. Small engines with spark a arrestor in the exhaust have this condition from flakes or rust blocking the fine screen . Don't know if this is possible on larger equipment.

Dave M7040

 

[Lobanz]

Sometimes it is a good idea to bypass a lot of the fuel system when you are having problems like you are. The typical trick is to get a squeeze bottle like on for mustard ( which I cannot stand) and fill the squeeze bottle with good diesel.

Arrange the fuel inlet to the injection pump so you can easily disconnect the normal line and connect your squeeze bottle with a long hose so you can sit in the drivers seat while squeezing the bottle to supply fuel. Other variations on this theme are possible such a a gas can and an electric pump all connected temporarily. Doing this will soon confirm if you have a fuel supply issue or something else even a restriction is the exhaust system. Small engines with spark a arrestor in the exhaust have this condition from flakes or rust blocking the fine screen . Don't know if this is possible on larger equipment.

Dave M7040

I'm gonna take all the rubber fuel hoses off and blow them out. Maybe even replace them. Since the fuel tank is about empty, I might can look in there and see if I see gunk. It seems that if the problem was a restricted fuel supply that it would manifest itself pretty quick and not wait 45 minutes to warm up. But I want to do cheap stuff before expensive stuff.

Thanks!


--- Lobanz

 

[Spanner]

I'm not convinced by your effort with the fuel filter & O-rings episode in Post #1.

Can you remove the filter bowl and re-check the o-rings fully?
Also, tip the fuel from the bowl into a container and visually confirm the absence of any water.

This won't cost you any money and gives a better datum-point to start from.

Pictures of the filter and o-ring scenario would be helpful.

Edit: I did watch the video - Too much movement of the throttle lever too frequently to be of much value. Set it on 'Max' and leave it for 1 minute.

Also: What chewed along the top of your instrument console?

 

[CalG]

When you last changed the fuel filter, did you observe water in with the fuel?

Perhaps a shot of dry gas would move any water through.

 

[Jerry/MT]

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

If you have a lift pump, many times they have a screen that can clog. However the intermitancy here makes me think there is something in your fuel tank that's restricting the tank outlet. It's probably barely buoyant and floating near the bottom and eventually gets on the outlet strainer and restricts the fuel flow.