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Discussion Starter #1 (Edited)
I have an LX-279 that keeps dying on my when it gets warm. In the last year I have replaced the fuel pump, carb, water pump, ignition control module, wire harness on the engine (not all to fix this issue but all done recently). Also replace the PTO because I had to break it to remove the motor to do the water pump. I can mow the lawn for about an hour or so. Then all of the sudden the tractor just dies like if you turn off the key. If I can push in the button to turn off the mower deck it will almost die and catch and run again. If I push the button to get the deck working again it typically will die. I am starting to wonder if it is a voltage issue? Any ideas would be amazing as other then this the tractor is working perfectly.

Thanks
Jon
 

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Discussion Starter #2
PS it does seem to be heat related because it will run longer when it is cooler and never has an issue when I am blowing snow.
 

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Check the battery and charging system. Especially when hot. I assume that your engine will crank over after it stalls but just won't restart.

When the engine dies. Remove the air filter and give the carb intake a shot of carb cleaner or starting fluid. Then try to start it. If it runs momentarily you have a fuel issue. If not you probably don't have spark. This should get you going down the right

If you have access to a compression tester. Do a test on both cylinders. This way you know for sure that the engine is capable of running correctly.
 

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Discussion Starter #4
Check the battery and charging system. Especially when hot. I assume that your engine will crank over after it stalls but just won't restart.

When the engine dies. Remove the air filter and give the carb intake a shot of carb cleaner or starting fluid. Then try to start it. If it runs momentarily you have a fuel issue. If not you probably don't have spark. This should get you going down the right

If you have access to a compression tester. Do a test on both cylinders. This way you know for sure that the engine is capable of running correctly.
Thanks for the ideas. I am starting to think that it may be voltage related. It just dies to fast IMO to be fuel related. I am going to try and bring home a volt gauge and test it again. Keep an eye on it. There are times when it dies that it will start right back up. Other times I have to crank and crank and crank and eventually it will start again. I did run a compression check and it is good. Other then this one thing it really runs perfect. If I can nock this out of the park I will feel good about putting some more money into the tractor because I have at this time done just about everything! LOL
 

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Thanks for the ideas. I am starting to think that it may be voltage related. It just dies to fast IMO to be fuel related. I am going to try and bring home a volt gauge and test it again. Keep an eye on it. There are times when it dies that it will start right back up. Other times I have to crank and crank and crank and eventually it will start again. I did run a compression check and it is good. Other then this one thing it really runs perfect. If I can nock this out of the park I will feel good about putting some more money into the tractor because I have at this time done just about everything! LOL
Definitely check it out with a volt meter before you destroy the part. At least be 80-90% sure it's your problem. The solenoid should have power when the ignition is on. The plunger retracts when the wire applies power to it. This allows fuel to flow.

The engine will turn right off. That solenoid is what kills the engine when you turn the key off. This is why the engine runs for a split second before stopping. It has to consume the fuel already on the intake side of the solenoid when it closes. We were debating this when the other guy had the problem. He had to use the choke to stall the engine by giving it to much fuel and not enough air. Another person suggested that a kill wire also shorts out the magnetos killing the spark to shut it down. My theory was that the spark is only killed by a safety system and not the key. Like getting off the seat without the brakes on or while the PTO is running. However the guy already got a new part and fixed it before putting this to the test.
 

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On the LX models when the key is shut off it cuts off the fuel solenoid and cuts off spark. However, there is a slight time delay to burn off a lil fuel. The spark gets cut off just a second or so after the key is shut off and the solenoid is cut off. Make sense?


Sent from my LGL52VL using Tapatalk
 

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Discussion Starter #7
On the LX models when the key is shut off it cuts off the fuel solenoid and cuts off spark. However, there is a slight time delay to burn off a lil fuel. The spark gets cut off just a second or so after the key is shut off and the solenoid is cut off. Make sense?


Sent from my LGL52VL using Tapatalk

I know the fuel shut off plunger is new as well at least in the last about year or so. Also tested it to make sure it was working. It is just odd that as soon as I shut off the mower deck that all of the sudden it starts to run ok again? If I start the mower up again as soon as it starts to run ok it will start to die again. If I let it run for a while with out the mower deck running and then start the mower deck again often times it will go for a little while then die again. So at this point I can only think that either it is somehow cooling off when it is running with out the implement engaged or it charges up the battery enough to run for a little while? I guess the volt meter will tell the tale?
 

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I would check spark on both cylinders with an inline spark tester. Plug one onto each cylinder and mow until it dies. Check for spark right away. If you have spark its likely a fuel issue. The engine consumes way more fuel with the deck running.

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I am just realizing I may have misunderstood your suggestions. Are you guys talking that the voltage is dropping and then the fuel shut off is engaging because of the low voltage?
 

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I would check spark on both cylinders with an inline spark tester. Plug one onto each cylinder and mow until it dies. Check for spark right away. If you have spark its likely a fuel issue. The engine consumes way more fuel with the deck running.

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I was always leaning at fuel issue but it is so odd that it runs perfect for over an hour or longer some times before it just starts to act up. Once it starts it continues to do it unless I just let it sit and cool down, rinse and repeat...
 

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I am just realizing I may have misunderstood your suggestions. Are you guys talking that the voltage is dropping and then the fuel shut off is engaging because of the low voltage?

This is a possible. However if the starter will crank away nice and strong it doesn't sound like a low power problem.

I'd try spraying carb cleaner into the carb after the engine dies. This test doesn't really cost you anything to perform. If it won't fire momentarily pull the spark plugs and check if they are all wet with fuel. If they are it is probably loosing spark.

Then I would perform the test with in line spark checkers as suggested.
 

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Discussion Starter #12
Like I said if I hit the clutch off it will catch and stay running. If it dies all I have to do it turn it over and it will start back up. So I don't think the starter fluid is going to tell us anything? Then when I engage the PTO again it will typically die again unless I let it run for a while with out the PTO engaged or let it cool down. Typically it will require me to let it cool down. I guess lets start with he volt meter and go from there.
 

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The reason I lean towards using spark testers is that I can see each cylinder. It will show strong or weak or cutting out. Dont get me wrong.. The carb cleaner squirt is a good one too and I use it too but if I want a definitive diag I use a spark tester. If you own a mower it needs to be in your arsenal of tools.

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Discussion Starter #14
So used it the other day with tools at the ready and 4 hours of mowing not a hickup! It was cooler but I was mowing wet heavy grass so the load was high. Try again later and hopefully it will be hotter out.
 

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Well still dealing with this problem and today I think I finally figured out what is going on. Was mowing the lawn today. Tractor died and this time no matter what I did it would not restart. I pulled the fuel line at the carb and there was no gas in it. I aimed the hose away from the tractor and turned over the engine and got no fuel out of the hose at all. I can see puffs of air but no fuel. This leads me to think that I am either having a vapor lock of some sort or there is a blockage in the fuel tank. My fuel filter is full of fuel. I have loosened the gas fill and that does seem to help.
 

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Saved me from typing Vapor Lock. Check how your fuel line is run so it is not near any hot spot but also check for pin holes in cracks they can stop the suction also if they leak to much.
 
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