john deere lx 279 stalls after 30mins?

[jsservant]

i have a john deere lx279 with 17.5hp liquid cooled kawasaki engine after running great for about 30 min it just shuts off almost like it runs out of gas, it will start back up but only runs for 10-15 seconds.
if you let it set all night you can get another 30 mins of perfect running then same thing
have replaced fuel filter,cleaned tank and refilled with fresh ethanol free gas,new plug,new gas lines
please help

 

[jsservant]

so no one has any ideas?
since the post i have replaced fuel pump and check and cleaned gas cap vent
please anyone i need help

 

[Lawnranger]

You have covered most of the basics but something is missing from the equation - spark or fuel. Test for spark when the engine acts up. To test for fuel, I use a can of carburetor cleaner and spray some right into the carb intake (air filter removed) and shoot short blasts to see if I can keep the engine running on the carb cleaner. If I can keep the engine running then I know I have a problem with fuel delivery.

So, which one is missing in your case?

 

[Mtn.Mike]

Is it possible that the coil has a crack in it. When the coil gets hot it expands and then when it sits it cools down and is usable again.
As another poster suggested, check for spark when the engine shuts down to rule out electrical problems.


Mike

 

[Rivets]

You don't say what engine you have. Does it have an oil sensor? Oil may be getting too thin due to age or wrong viscosity (if it is a pressure sensor) when it reaches operating temp causing the engine to die. Same could be said about a temperature sensor ( if you have one ) and the engine is overheating.

 

[jsservant]

sorry it has the 17.5 hp kawasaki twin liquid cooled engine ok soon as it died i checked for spark it was good also pulled gas line and checked to see if pump was working it is. it will start right up every time but dies in like 30 seconds

 

[Lawnranger]

sorry it has the 17.5 hp kawasaki twin liquid cooled engine ok soon as it died i checked for spark it was good also pulled gas line and checked to see if pump was working it is. it will start right up every time but dies in like 30 seconds

Ok, now that you determined that spark is good you are narrowing down the possibilities. Next, go back to my post about the carburetor cleaner and perform that test and make sure to post the results.

 

[jsservant]

ok got it running, did the carb cleaner test and could keep it running ,
so after checking my lines again i decided to try running them different so took some tie straps and ran the line against the hood making sure to keep it away from the engine completely and the result.
we have a winner.
was told it could be the gas was evaporating between the filter and pump enough to cause the problem with the line ran against the engine like it was.
which i dont understand being that it was ran that way by the factory.
but its running so ok

 

[Lawnranger]

Technically the only way gas could evaporate is if there is an external leak. Most likely the problem is vapor lock in which the liquid fuel vaporizes in the line due to excess heat. Just for fun, put the machine back to the way the factory built it but replace the rubber fuel line with new. You will need to drain the fuel tank so make sure to have a large fuel container handy. You can use a vise grip to gently squeeze the old fuel line to stop the flow while you are moving the line to the fuel container. After you replace the line (make sure to use the correct fuel line) put just enough fuel from the container back into the machine and try it again. If you experience the same problem then try using a higher octane fuel and see if that helps. Another possibility is that your pump cannot pump enough volume to keep up. However, you say you have it fixed so congratulations on fixing it and hopefully it will stay that way.

Let us know.

 

[jsservant]

o.k. new issue, its still running but if i start up any incline it starts missing so bad i have to kill the pto and it will stay missing untill i get it turned around facing downhill????? only does this on inclines on level ground runs great
sorry to be such a bother