CK20s loses power 20 minutes into heavy lifting

[DroppedAxle]

Hi All,

I have a 2007 CK20s that runs just fine for my summer tasks. However, when I used it to plow the 2.5' of snow we got yesterday off a 600' drive, the engine loses a lot of power 20 or so minutes into the job. It goes from about 2300 rpm to 1000 rpm and then fluctuates all over the place. This occurs while "plowing" snow with the loader and the drop in power usually happens during or right after a heavy lift and dump.

Once I let the machine cool down, it will give me another 20 minutes or so of hard work -- then the same thing. Note that the engine temp gauge is in the normal zone so there's no engine overheating, but maybe some component is getting too hot? The outside temps were 26-32F when this occurred yesterday and today.

I think the diesel is OK. Last winter I had icing in the fuel filter, but I've been treating always and the fuel in the filter and tank seems fine. In the morning I start the machine, let it idle for 30 minutes before starting work. 20 minutes later after heavy lifting, low power. The fuel lines were all cold from overnight so I don't think it's water in the fuel.

Anyone with ideas on what could be going on with my machine?

Thanks,

DroppedAxle.

 

[ritcheyvs]

Sounds like a fuel obstruction or possibly a failing lift pump (less likely). The obstruction could be frozen water (or other debris) in the fuel tank or a plugged fuel filter. You might try disconnecting the fuel line at the input to the lift (fuel feed) pump right after the problem occurs to be sure you get healthy gravity flow at that point. A plugged fuel tank vent would have similar symptoms but would also collapse the tank.

 

[DroppedAxle]

Thanks, Ritchey,

Yes, definitely a fuel problem. Yesterday I was putting a heat gun onto the fuel filter for 5 mins since the winter before I had ice there. No ice this winter since I've been treating my fuel generously. This morning, I did not put the heat gun on and the tractor lost power almost right away (after having idled warmup for 15mins at low rpm). I then put the heat gun on for 5 mins, and bingo, I get 20mins of use out of it. So I'm guessing the heat makes the diesel less viscous so it gets around any pebble that may have found it's way into the line. I'm guessing the obstruction is the fuel filter or downstream from it.

I'll redo all the lines up to and past the lift pump which I'm guessing is the thing in the attached pic.


Thanks for your help. If anyone knows of a post or guide on how to clear and reset the fuel system on such a tractor, I'd be much obliged.

-DA

 

[ritcheyvs]

DA: Yes, that is the lift pump. This is a simple diaphragm pump that supplies fuel to the injection pump at a couple PSI.

Your symptoms read more like ice in the filter. Have you tried changing (or even dumping out) the filter? It might be fuel jelling too but less likely. Did you buy that fuel after cold weather? Winter Diesel is formulated to be less vulnerable to jelling. The small amount of additive is probably not enough to prevent a whole tank of Diesel from jelling. But your temps aren't all that low so I think water in the fuel is more likely to be your problem. Remember that the fuel in the tank will be quite cold after standing all night.

Your owners' manual should show how to purge air from the system after replacing the fuel filter. Your's may be different but on my DK, it's best to pre-fill the new filter with fresh fuel and then turn the valve (on the filter housing) to purge and (after a few minutes) run the engine a brief time. Finally, turn the purge valve back to normal. The drawings in the manual are almost useless but it's a lot clearer looking at the actual filter housing. In the purge position, air and excess fuel goes back to the fuel tank as gravity and the lift pump fill the filter. Pre-filling the new filter makes this go much faster.

 

[tman1020]

Be sure to check the air filter to. Mice like to find all kinds of places to keep warm and nest up.

 

[DroppedAxle]

Thanks, no mice in air filter :thumbsup:

Could it be that my fuel system needs to be bled? When I had ice in the filter last year I did remove it to get all the crystals out and put it back filled with 1:1 diesel 911 emergency formula. I did not bleed the system then and it ran fine all sumer. Fuel filter on the machine is full of fuel, no icing visible.

DA

 

[ritcheyvs]

If you have a couple empty Jerry cans, you could drain the old fuel into those cans and save it for next summer. Then get a few gallons of new Diesel and put it in the tank. But if you have a new fuel filter on hand, I'd recommend changing the filter first. That might solve the problem. If you suspect water in your fuel supply, you might get one of those funnels that boaters use; those funnels trap water before it gets into the tank. World-cruising boaters are often forced to buy fuel from questionable sources so they use those funnels to trap water and crud.

 

[VictorW]

If it ran all Summer without a problem, there shouldn't be any air or need bled. It does seem like you're getting moisture from somewhere and it's freezing up or you got a bad batch of fuel. It's odd though that the same thing happened to you last year. It there a place in your fuel tank that could hold water and mix occasionally with the diesel? When I need to depend on a machine to work, like now in Winter, I don't play around with try this and then try that. I'd drain all the fuel from the tank and hoses, put in a new fuel filter and new diesel like ritcheyvs mentioned. Filter the old fuel later if you want.

 

[DroppedAxle]

Thanks Victor.

Let me clarify, last winter was my first with a diesel machine and I had not treated the fuel. Also, it was wicked cold, in the single digit for weeks on end. This episode was mid-20s to lower 30s. Last winter it was obvious - the filter was jammed with ice. Nothing I can see this winter.

What sets it off this time is the machine really straining to lift a bucket of snow. The rpms drop to 1k and even if they recover to 2k+, the slightest bit of load will drop them again. Putting a heat gun onto the air filter for 5mins will give me another 20mins of full power. The engine is always in its normal temperature operating range.

I will dump the filter when I have time on Wednesday and report back. Napa is recommending this part of theirs, which I will try to locate: NAPA AUTO PARTS

 

[Ranchofla]

Thanks Victor.

What sets it off this time is the machine really straining to lift a bucket of snow. The rpms drop to 1k and even if they recover to 2k+, the slightest bit of load will drop them again. The engine is always in its normal temperature operating range.

I will dump the filter when I have time on Wednesday and report back. Napa is recommending this part of theirs, which I will try to locate: NAPA AUTO PARTS

I have seen this behavior with my CK20 in the summer and it was a very dirty fuel filter. I would definitely change the filter.

Rancho