Dexta loses power when warm

[native]

I have a 62" Dexta. The last two times I went out to mow pasture this spring the motor loses power and almost dies when the motor gets warm. The temperature guage is not reading hot. The motor has plenty of coolant. Over the winter I replaced the fuel pump that supplies fuel to the injection pump. The tractor ran fine during the winter months. It seems like its runnning out of fuel when it gets warm. I did bleed the fuel system after replacing the pump. Any suggestions on what the problem might be and how to troubleshoot would be greatly appreciated. Thanks in advance - Tom

 

[Dandy Dave]

Did you change the fuel filter? Dandy Dave!

 

[native]

Yes, I changed the fuel filter when I replaced the pump. Last night I removed the line that supplies fuel to the pump and I have plenty of flow from the fuel tank. I reconnected the line and bled the air from the both ports on the fuel cannister and the injection pump. I did not work the motor hard enough to get it heated up to see if it has the same symptoms. This weekend I'll have time to do more mowing and see what happens. The only thing I can figure is I the fuel pump I replaced is faulty?

 

[Dandy Dave]

I wonder if you are getting a piece of dirt that is partly blocking the fuel flow in the bottom of the tank but not all the time. Had this problem with a backhoe not that long ago. Pieces of the fuel gauge float were blocking the flow of fuel, but would float up when it was stopped. Sometimes you never know what is in the bottom of a fuel can. The pump should have a hand primer. Pull off the line and see if you are getting a good flow when you pump it. Also, see if it flows when turning the engine over with the starter. Dandy Dave!

 

[native]

Hi Dave,
Thanks for you help. I did look into the tank holding a match(just kidding). I had a bright flashlight. The tank looks really Clean.

 

[native]

I spent about an hour mowing yesterday during which the motor ran normally. When I finished I stopped to talk to a friend and let the motor idle. About 2 minutes later the motor died and would not restart. I pulled the fuel cap(which I replaced last winter) and it had a lot of vacuum on it(5 to 10 lbs). I then pulled the line feeding the fuel and had lots of flow. I pulled the line leaving the pump and cranked the motor and it seems to be pumping plenty of fuel. I had my friend crank the motor while I bled the fuel system and it started and ran like a top. I'm obviously getting air into the fuel system, what I'm beginning to suspect is the fuel cap creating the large amount of vacuum is forcing air to be drawn into the fuel system? I'm going to try my old cap that never had a vacuum on it. Has anyone ever experienced anything like this? Any thoughts on this would be appreciated. Thanks

 

[Brian Allen]

Native
Sounds like you have found the issue; you must have the tank vented.
Try another fuel cap to see if that fixes it.
Brian

 

[Dandy Dave]

Sometimes I have taken a newer cap and had to to drill vent holes in them on different applications. Seems like the last place that you would look. I also think that you have found the problem. Dandy Dave!

 

[John B.]

Has any work been done to the fuel pump?

What type of pump does it have.

I don't mean to sound sharp, I'm just trying to help diagnose the problem.

 

[WayneB]

I have two Dexta tractors, with fuel caps that don't seal perfectly with a full tank. I never fill to top. I had been thinking about buying a new caps, but after reading your post, see myself as not having a problem with my venting and worn old caps.
Wayne

 

[native]

I cut a small slot in the rubber seal on the new fuel cap and spent several hours loading and spreading manure last night. It never missed a beat! Thanks everyone for all your suggestions.