2013 Cub Cadet LTX 1050 KW Won't Stay Running

[CobyRupert]

BUT, it does run for a sustained period of time now AS LONG AS I start out with a full tank of fuel. Once the fuel gets down to 1/3rd - 1/4th full, it stalls out as before. So, I guess a cheap repair would be just to keep the fuel leve up. However, I really would like to get to the root cause and fix this thing. Any ideas? Thanks.

Symptoms of a bad tank vent are usually opposite: Engine more likely to quit when tank is full than when nearing empty.

So....the question is what changes when either 1) Warm and/or 2) Low tank level?

I heard of fuel lines (perhaps vacuum line too?) that once they warm up because of proximity to motor or exhaust get pliable enough that they collapse (pinch themselves), especially if they have a suction being applied.
Can the gas tank feed the carb by gravity when it's full, but once fuel gets down it NEEDS the pump (that for some reason isn't working, or doesn't work when warm)?

I'd test that the pump, or vacuum line to pump, is actually working.
Double check that something in tank does float/sink to block outlet, then floats away.
Could still be vapor lock (fuel line to close to heat).

 

[KountryKevin]

Thanks for the insights. I thought a couple of pictures might help.

I have replaced part 49040 (fuel pump) and tubes 92912, 92192A and 92912B.

I also swapped out part 21188 (solenoid).

Part 11013 (air filter) was changed and is clean. Question on the diagram with this part: Check out part 92066 (plug). What is its function? I can't recall the effect right now, but it seems to me that I ran the tractor with the plug both on and off.

I'm not seeing anything labelled vacuum line. Can you tell which part it is on these diagrams?

Thanks again.

 

[tomplum]

As Coby noted. I've seen a few of these Cub with the under hood tank plug at the outlet with debris and ... flies too. Creates an intermittent block that the pump can't overcome.

 

[Bob_Bainbridge]

Your symptoms point to some kind of problem with the fuel supply. You've exhausted most of the possibilities so I would possibly look at a fuel hose problem. Look for kinks, soft spots etc. Sometimes the inside of the hose collapses restricting fuel flow. To prove it maybe you could get a length of hose and temporarily just run it from the tank to the fuel pump. If that doesn't help try replacing the line from the pump to the carb.

Bob B.

 

[Richard001]

Thanks for the insights. I thought a couple of pictures might help.

I have replaced part 49040 (fuel pump) and tubes 92912, 92192A and 92912B.

I also swapped out part 21188 (solenoid).

Part 11013 (air filter) was changed and is clean. Question on the diagram with this part: Check out part 92066 (plug). What is its function? I can't recall the effect right now, but it seems to me that I ran the tractor with the plug both on and off.

I'm not seeing anything labelled vacuum line. Can you tell which part it is on these diagrams?

Thanks again.

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Tube 92912 that attaches to the bottom of the pump is what some people call the vacuum line,it's actually a pulse line. As the engine crankshaft rotates and the pistons move up and down, there are pressure and vacuum conditions inside the crankcase. The pump uses these pulsations to pump the fuel. When there is pressure in the line, the pump forces fuel out, when there is a vacuum in the line,it sucks fuel from the tank.

I would check the fitting in the engine that the pulse line goes to, to make sure that it is not plugged.

Richard