I've owned the tractor since new 2008 model X749. 550 Hours. I mow 3 acres with lots of WV hills. I get it serviced every year by the dealer. It started last year, after an hour it would sputter and die. It has gotten worse and is now down to 20 minutes. It feels like someone cuts off the fuel. Once it dies it does not want to start until you let it cool down. Cooling the engine, pumps, hoses, and components with fine water spray for a couple minutes will buy me another 10-20 minutes of run time so I think its external to the engine. It dies more going down hill then up hill. Once it dies going down hill I can restart it and mow uphill (forward/reverse/repeat) for another 5 minutes but it will die going up hill when it gets hotter. It doesn't matter if its 85 or 60 deg outside, I get 20 minutes of run time. The engine temp is quite different and the other morning wasn't even half way on the gauge. heat gun shows injector pump shuts off the first time at 175 deg, with the 3 injector supply lines at 180. After cooling with garden hose the injector pump shuts down the 2nd and 3rd time at 150 to 160 with supply lines at 165. So I don't think its injector pump. The fact the cool water immediately fixes the problem makes me think its not the injectors themselves.
I've replaced the filter and fuel solenoid.
Checked all hose connections.
I added a 12v pump between the tank and lift pump to make sure I was getting positive fuel pressure to the injector pump and not having any leaks.
I tightened the screws on the lift pump housing (got 1/4 turn on each of them)
I've topped off the tank to make sure the supply line inside was not getting air.
I have ordered and will be replacing the following:
Fuel bowl and o-ring
All 3 braided hoses
I've read a lot of posts about this tractor dying and a lot of suggestions. However none of them with my symptoms.
1. It happens when one of the external components gets hot
2. It shuts off downhill at a lower temp then up hill
3. fine mist cooling of components resets it.
Do I need to:
Remove fuel Solenoid and put in a manual fuel valve?
When I changed out the solenoid for the first time, I got an hour and thought I had it fixed, but it went right back to what it was doing. Do I have a bad battery and did it burn up my new solenoid?