Tractor loses power

[fruitcakesa]

Lately, when driving up slope, the engine will lose power to the point that in order to keep forward progress, I have to back off the throttle to maintain headway. As soon as it starts to level off, power returns.
Today, it also lost power on a downhill run and cleared up when back on the level.
I use freshly treated fuel with power service.
Any ideas

 

[PaulR]

Try low range.
Does the trans feel like its slipping?

 

[DevilDog]

Lately, when driving up slope, the engine will lose power to the point that in order to keep forward progress, I have to back off the throttle to maintain headway. As soon as it starts to level off, power returns.
Today, it also lost power on a downhill run and cleared up when back on the level.
I use freshly treated fuel with power service.
Any ideas

What range are driving in? Maybe you need to change into a medium range?
Devildog

 

[kubotafreak]

Fuel separator inlet should be checked. Air in the seperator bowl is a good indicator of a restriction in fuel delivery.

 

[fruitcakesa]

Try low range.
Does the trans feel like its slipping?

No, just that it loses power

 

[fruitcakesa]

What range are driving in? Maybe you need to change into a medium range?
Devildog

Low range

 

[fruitcakesa]

Fuel separator inlet should be checked. Air in the seperator bowl is a good indicator of a restriction in fuel delivery.

I have to check that.

 

[Mark_BX25D]

It's a diesel. Loss of power is one of three things:

1. Loss of compression.
2. Loss of air supply.
3. Loss of fuel supply.

Since yours comes and goes, it's not #1.
Since it's hard to imagine an obstruction in the air supply that would come and go with slopes, it's almost certainly not #2.

That leaves fuel. Hmmm. Liquids sloshing in a tank.... flow changing with slope.....

Yeah, that sounds like fuel.

I'd be looking at your fuel tank.

 

[JerryMT]

Lately, when driving up slope, the engine will lose power to the point that in order to keep forward progress, I have to back off the throttle to maintain headway. As soon as it starts to level off, power returns.
Today, it also lost power on a downhill run and cleared up when back on the level.
I use freshly treated fuel with power service.
Any ideas

Sounds like you may have restricted fuel delivery. Start at the line that delivers fuel to the injection pump (or the high pressure pump) and work back toward the tank. You should have gushing fuel flow through the lines at every point in the fuel circuit. When is the last time you changed the fuel filter? Are you in a cold climate where icing or fuel waxing might be an issue? DO you have winter fuel in the tank?

 

[fruitcakesa]

Sounds like you may have restricted fuel delivery. Start at the line that delivers fuel to the injection pump (or the high pressure pump) and work back toward the tank. You should have gushing fuel flow through the lines at every point in the fuel circuit. When is the last time you changed the fuel filter? Are you in a cold climate where icing or fuel waxing might be an issue? DO you have winter fuel in the tank?

It is cold here, and have yet to start checking specific items
I always use fresh fuel with power service in winter.

 

[BAP]

Check your tank cap, could be not venting properly. With it as cold as it has been, the inside of the cap could be frosting over or the rubber that moves to allow air in may have become too stiff in the cold to move.

 

[fruitcakesa]

OK, so I changed out the fuel filter and cleaned the fuel strainer
Pumped up the filter till it was hard to push the pump, filled the fuel strainer and then started it.
It ran for a minute, then began to stumble. I was able to keep it running and started to drive it back to the shed when it stumbled again and then quit.
I have not been able to restart it since.
It will crank fine but no start.
I opened the fuel cap in case that was the issue but no go.
I am stumped [being relatively diesel ignorant].
This is a real problem with a winter storm on the horizon.
Any help is greatly appreciated

 

[JerryMT]

OK, so I changed out the fuel filter and cleaned the fuel strainer
Pumped up the filter till it was hard to push the pump, filled the fuel strainer and then started it.
It ran for a minute, then began to stumble. I was able to keep it running and started to drive it back to the shed when it stumbled again and then quit.
I have not been able to restart it since.
It will crank fine but no start.
I opened the fuel cap in case that was the issue but no go.
I am stumped [being relatively diesel ignorant].
This is a real problem with a winter storm on the horizon.
Any help is greatly appreciated

Did you check the fuel supply circuit from the main injector pump back to the tank? There are lots of places for fuel restrictions like the filter head (which supplies fuel to the filter), fuel lines, etc. That's why checking at the injector pump inlet is the place to start. If you don't have gushing fuel at that point you clearly have restricted fuel delivery. If you do have gushing fuel, then your problem is elsewhere.

Is there anything in the fuel supply circuit that could have a filter like a lift pump may have an internal screen? What about lines and fittings where clogs can occur. Do you have a separate water separator? Check that if you do.

Do you have a fuel shut off solenoid? Does it stay open when you get the engine started? They generally have two solenoids one for opening the fuel valve and one for holding it open long term.

If you're going to get this running before the storm you need to do some good diagnostics to locate the root cause of the problem. No short cuts. None of us can help you at a distance except by offering advice!

Good Luck!

 

[North Idaho Wolfman]

I'm a little lost?
If this on your M6040?
I don't see a hand pump on the fuel system?
With so many variations anything is possible.

 

[North Idaho Wolfman]

I'm a little lost?
If this on your M6040?
I don't see a hand pump on the fuel system?
With so many variations anything is possible.

Ok had to dig deeper found the pump.

To get it to the shop, bottle feed the injection pump.
Turn off the fuel at the separator / strainer,
Pull the fuel line off at the side of the injection pump ( the one that comes from the fuel filter) and attach a line to a bottle suspended above the injection pump.
This will get it running and into the shop or place to work on it.
Then when you have it there.
Connect a short hose off of the fuel filter into a container, start it, open the fuel cock at the strainer.
what you should be getting is a constant pulse of fuel, if you not shut it off and check for fuel flow at every point starting at the fuel filter working back.
If you have fuel flow, you have a bad / clogged/ damaged fuel lift pump.
If you don't have a good flow you have a clog, go to the last point of flow and the part before it is clogged.

 

[fruitcakesa]

Ok had to dig deeper found the pump.

To get it to the shop, bottle feed the injection pump.
Turn off the fuel at the separator / strainer,
Pull the fuel line off at the side of the injection pump ( the one that comes from the fuel filter) and attach a line to a bottle suspended above the injection pump.
This will get it running and into the shop or place to work on it.
Then when you have it there.
Connect a short hose off of the fuel filter into a container, start it, open the fuel cock at the strainer.
what you should be getting is a constant pulse of fuel, if you not shut it off and check for fuel flow at every point starting at the fuel filter working back.
If you have fuel flow, you have a bad / clogged/ damaged fuel lift pump.
If you don't have a good flow you have a clog, go to the last point of flow and the part before it is clogged.

Wolf, thanks for the specific info on getting it going.
I am hoping it is just a clog or trapped air and not something electrical or other.
We are looking at potential major snow, high winds and deep freeze tomorrow.
We'll see how it goes.

 

[fruitcakesa]

Did you check the fuel supply circuit from the main injector pump back to the tank? There are lots of places for fuel restrictions like the filter head (which supplies fuel to the filter), fuel lines, etc. That's why checking at the injector pump inlet is the place to start. If you don't have gushing fuel at that point you clearly have restricted fuel delivery. If you do have gushing fuel, then your problem is elsewhere.

Is there anything in the fuel supply circuit that could have a filter like a lift pump may have an internal screen? What about lines and fittings where clogs can occur. Do you have a separate water separator? Check that if you do.

Do you have a fuel shut off solenoid? Does it stay open when you get the engine started? They generally have two solenoids one for opening the fuel valve and one for holding it open long term.

If you're going to get this running before the storm you need to do some good diagnostics to locate the root cause of the problem. No short cuts. None of us can help you at a distance except by offering advice!

Good Luck!

Thanks for the advice. I have some digging to do.

 

[RCW]

fruitcake - - - I don't to profess to have any specific knowledge....just trying to help.

Many times guys have found crap in the inlet fittings going into the separator housing. Not evident in the separator itself, as it's before the housing the separator screws into.

Recall it to be a 90 degree fitting going into the top housing?

It's hay pieces/crap plugging the fitting(s) into the housing.

@kubotafreak mentioned it earlier.

Recall it more commonly with some of the "L" series, but maybe same for an "M" as well??

Again - - may be way off, but thought I'd mention it......

In all sincerity, best wishes.....

 

[Thunder chicken]

^ good advice. This is what a dealer recommended me to check a while ago…..
I found dirt in fuel tank (a piece of foil from the power service bottle cap!) blocking the suction line… occasionally…..

 

[Mark_BX25D]

Have you verified the pump is actually pumping?