# What The



## Effinay (Dec 6, 2009)

Been having a pretty good winter thus far, that was until now. First year for owning and operating a loader/backhoe and have been proactive with keeping the fuel tank topped off, using fuel stabilizer, and keeping the battery charger plugged in. This is a diesel tractor mind you and doesn't fit in my garage. Pushing back piles in anticipation of the next "big one" the engine starts surging and losing power after using it for about 45 minutes. I thought, dirty fuel filter, lets have a look. Filter is a clear glass gizmo with a paper element inside. Didn't look horrible but I noticed lots of small air bubbles in the top/outlet side of the filter. Not sure where they were coming from, but just made a mental note. Changed the filter and wouldn't you know the same thing started happening with the surging and loss of power. Before the thing quit on me I got out and saw the bubbles again and this time they seemed to be being pumped into the filter. I listened to the motor surging and watched as the bubbles dissipated and the motor smoothed out. As soon as I put the power to it, same thing. This thing will sit there and idle all day long with no problem, run it for half an hour at speed and now I got issues. Oh by the way, the fuel pump (mechanical) was replaced about 5 yrs ago. I'm thinking the guy who owned this before me must have had the same problem. Anybody got any ideas?


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## Cover Guy (Sep 30, 2009)

Sounds like you could have a pick up line going bad


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## Effinay (Dec 6, 2009)

I haven't done anything more with it yet, but I was going to trace the lines back to the tank and look for any fittings that may be loose. Thanks for the response.


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## tailboardtech (Feb 28, 2010)

i am with cover guy you have an air leak somewhere i would start by checking all the hose clamps and go from there


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## Effinay (Dec 6, 2009)

I'm thinking that the fuel supply lines are steel except for wher this machine articulates. That may be where there could be a loose clamp or fitting. To cold and dark to mess with that tonight, I'll get a look at it tomorrow. Thanks for yor help.


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## mrv8outboard (Dec 29, 2009)

They are correct with the air leak. You can pull air in easier than fuel can leak out. There is one more possibility, you could have a restriction in the fuel line causing the atmospheric pressure to drop in the line causing the fuel to boil IE air in the line. Some tanks have a screen in the dip/siphon tube that can clog up.


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## Mister Plow (Jan 21, 2009)

Are there any quick connectors on your fuel lines? I've seen one that had a leaf sucked in the line and it plugged up the quick connect. Had to take the connector off the line to find it. 
Or if there are any other possible restrictions in the line where something could get caught up.


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## nycpsd (Nov 17, 2009)

Just a thought on something that happened with our machine was we used 5 gal cans to fill the fuel and the inside of the fuel can delaminated and clogged the pickup in the tanks.


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## snow game (Sep 28, 2008)

sounds like your sucking air to me as well. I have had simmilar problems like this over the years, some of the causes were:
clogged "sock" filter at the end of the pick up tube in the tank.
Bad lift pump.
Bad o rings on the fuel lines.
Having simmilar problem on my deere right now. Runs like a top for about 1 hour then loses power.. If I pump up the primer on the lift pump it will correct itself for about 15-25 minutes then I have to keep pumping it up. Best way to find the problem is to temporarily by pass one line at a time (or part of one line) to rule it out. a quick fix you could try is blowing air into the tank. if its cloggged that will clear it temporarily.
Another cause was the steel line slightly rotted (not bad enough to leak but was porus enough to suck air) where it enters top of tank.
A simmilar power problem I recently encountered, was I had a truck and a backhoe go down the same night. both tanks were air bound. The dump was so bad it collapsed the tank. The backhoe wasn't as bad but started losing power and had black smoke, loosened the caps and they ran fine. Never seen that in 27 years and it happened twice in one night.


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## Effinay (Dec 6, 2009)

*What the F*



snow game;1245092 said:


> sounds like your sucking air to me as well. I have had simmilar problems like this over the years, some of the causes were:
> clogged "sock" filter at the end of the pick up tube in the tank.
> Bad lift pump.
> Bad o rings on the fuel lines.
> ...


Thanks for those nuggets of info. It sounds as though you might have had quite a night when all that went to hell on ya. With this little break in the weather I'm going to get a closer look at the fuel lines and check for the obvious stuff first, loose fittings, clamps etc. This is an older machine and I've only owned it for a short time. Not to mention this is my first diesel so I've got much to learn. Thanks for your interest and help with this.
Regards,
J-


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## IC-Smoke (Feb 15, 2008)

I ran into the same thing on my cousins 580E, turned out to be a bad lift pump.


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