Constant dying. Air in fuel?

[XR4140]

Posted here a few times with multiple issues about my LS XR4140 with 535 hours.

Had a past issue where the dealer wouldn't help with constant dying and limp mode with the tractor. Not regening etc etc

Finally they update the computer (I guess) and the thing can regen. I had high hopes the constant dying was fixed too, but its still happening. (at least just 1 code instead of 4 now lol)

Its all the time but totally random, it will die and say F11 157. Today it died with no code for the first time.

Finally figured out that if I unscrew the drain on the bottom of the fuel filter....it would let air out. It will then fire right up again and keep working until it dies again later.

It tells me there is air getting in the fuel system...but I dont see anything that looks bad. Or am I wrong? Any ideas on wait to look for beyond typical vacuum type hose damage?

Any help is appreciated. Thanks

 

[TnAndy]

When it dies, pull the hose coming from the fuel tank off and see if you have a good flow of fuel. Many times 'dying' is a tank obstruction. The air you see in the filter bowl can be a vacuum..if it's a plastic bowl, you can see the sides of it suck inward slightly as the fuel pump tries it's best to get fuel.

 

[sodamo]

Check the moisture sensor. Bottom of fuel filter. Forget the codes, but after I replaced mine and the fuel filter no more problems. Mine never died completely just go into limp mode.
Maybe just take it apart and clean.

 

[Underdog57]

Check to make sure your fuel tank cap is venting properly?

 

[bruceatlam]

If the fuel cap isn't venting properly, the first thing you'll notice is that the tank itself will show evidence of the vacuum ---- i.e. it will look a bit concave.

 

[Avenger]

Fist things first. Make sure your air bleed valve located at the top of the fuel filter is tight!

Fuel system needs to be examined very thoroughly. I'd replace the fuel line from the tank to the filter at minimum.

Replace your cap. Checking it for ventilation is one thing, but how do you do that exactly? Replace it and know that issue is no more.

Clean the fuel tank. While you have the fuel line off, consider dropping your fuel tank and cleaning it out. Its not very hard to do. I suspect there is debris that is blocking the output port.

Drain all the fuel/water from the fuel filter/moisture sensor. Take the moisture sensor off and clean it. You said you are seeing air at the BOTTOM OF THE FILTER?! That is odd. Air rises, so it should be at the top of the filter where the air bleed valve is.

If you do all this, and the system is still malfunctioning, get some length of fuel line, a 12v fuel pump, and bypass the filter assembly all together. See if you are getting enough fuel pressure to the rail that way. To do this, dip one end of your fuel line into a diesel can full of fuel. Dont use your tank (that is still suspect). Run that line into your solid state fuel 12v fuel pump like this one: Amazon.com: Facet New Solid State Fuel Pump 12V 3-4.5Psi, 12" /3.48Cm Min Dry Lift 6558398 D72347: Automotive (its a bit spendy, but has other uses outside of diagnostics), connect the output hose directly to the fuel rail. Hook the pump up to some small alligator clips and connect to your battery. Make sure your bleed your new bypass before attempting to start the tractor.

This bypasses so many things, but dumbs down the system. MAKE SURE YOU USE CLEAN FUEL FROM A CLEAN CAN AS THERE IS NO FILTER INLINE!
If your tractor runs normal, then you know the problem is somewhere you bypassed. If not, then you know its likely your injectors. Work your way backwards from the rail to isolate the issue. Do not run the tractor bypassed for doing work. This is for diagnostics only. I can just see someone bungee cording a 5gl fuel can with a hose sticking out of it, a zip tied fuel pump hanging from the frame, out in the field. :laughing:

Good luck and please let us know what you find.

 

[XR4140]

Thanks for all the replies, I will report back.

As fair as the air at the bottom of the filter:

When I unscrew the water drain at the bottom of the fuel filter (after dying) it lets out a pshh sound like air...then gurgle. Will start right back up.

 

[mred2]

The sound you are hearing most likely is a vacuum. Air going in. Remove fuel cap and try it next time without unscrewing the drain. That will test the fuel tank vent.

 

[Avenger]

The sound you are hearing most likely is a vacuum. Air going in. Remove fuel cap and try it next time without unscrewing the drain. That will test the fuel tank vent.

^this^

 

[XR4140]

Worked the tractor hard this weekend.

Died again like usual. I opened the fuel cap as suggested and still would not start. Then I opened the fuel drain again to hear the loud pshh sound then gurgle....then it started back up. Same thing its been doing.