Can't keep fuel flowing on JD 855

[kimodc]

Hello, I need help with my JD 855. I cannot keep fuel flowing, as the level slowly drops in the fuel filter bowl until it starves out. It is a later model so it has the mechanical fuel pump which seems to be working fine. I can get the bowl to quickly fill if I bleed the air out of the bowl by loosening the middle screw on top of the fuel filter, but when I close it back up, the fuel level starts to drop again. It does not always drop at a constant rate, sometimes faster then other times. I have blown out all the lines, checked for any leaks and can't see any. The only thing that will keep the bowl full is holding my thumb over and plugging the return line to the tank. This builds pressure in the return line, but seems to keep the bowl full. Also, if I go to manually pump fuel into the bowl with the little lever on the side of the fuel pump, it will rise the level slowly, but then quickly drop again.

Any help would be sure be appreciated, as I have been scratching my head a while on this one!

 

[beenthere]

You say "until it starves out". Not sure if this means the bowl empties and the engine keeps running OR the engine dies from lack of fuel. Which would happen?

 

[kennyd]

Will it stay running with the fuel cap off? The vent could be plugged...

 

[kimodc]

The bowl empties and the engine runs out of fuel.

I tried with the fuel cap off, no difference

 

[joecdeere]

Trash stopping up the tank outlet, or inside of fuel lines breaking down?

 

[jd110]

There is a screen in the fuel tank on the end of the pickup tube. Have you pulled it out and cleaned it? If not then I am betting that is your problem. It is item 11 in the diagram. I pictured the mid mounted tank. If the front tank, it has the same screen.

 

[kimodc]

I'm not sure if I solved the issue or not. My pick up and lines were all clear, although mine does not have the screen (11) or (13) on the end of the pickup, (probably in the bottom of the tank). What I did was bypass the fuel filter apparatus and used a clear inline filter. It seemed to work better as it stayed full of fuel when running . I then took off the mounted fuel filter, took it all apart and blew air all through it and it seems to be working okay now. I don't know if this solved the issue of not, but it ran okay for the next half hour, so we will see.

I appreciate all the suggestions, but hopefully we got this one solved!
Thanks,
Kim