L35 fuel issue - runs 10-12 minutes then quits

[Jelf]

I replaced the fuel filter on my L35 and then spaced out and forgot to open the fuel shutoff valve. Instead, I hoped on and went back to work hauling firewood. Before long the tractor began to lose power. I was just able to limp it back to the barn where it now sits.

In due course I realized my mistake and opened the fuel shutoff valve.

Thinking that air may have gotten into the fuel lines as a result of my brain-dead goof, I have bled the fuel lines three times by loosening the 3 nuts that secure the fuel lines to the top of the injector assemblies and cranking the engine till a bit of fuel comes out of each line. Thanks to this site and the video that showed me how to do that!

The engine then starts fine and runs great until it once again loses power after 10-12 minutes, idles way down, sputters and quits. There is plenty of fuel in the fuel tank and I have carefully cleaned the fuel tank cap.

The fuel filter is in a clear plastic bowl and it is always full of fuel.

I could sure use a tip for what I should check next

 

[Stumpy]

Did you bleed the injection pump too? Could be air still in there. What usually causes that symptom is a restriction in the fuel supply to the injection pump. If burping the pump doesn't work make sure the lift pump is functioning properly and the bottom of the tank isn't full of crud.

 

[Jelf]

Thanks Stumpy. I'll try bleeding the injector pump tomorrow and report back.

 

[Jelf]

I finally had a chance to work on this some more.

First I pulled the two fuel return lines off their nipples at the top of the fuel tank. I pushed a small diameter stiff rod through each one to make sure they had not got obstructed inside the tank somehow.

Then I opened the bleed valve on the injector pump and started cranking the engine for the recommended 10-15 seconds. After about 3 seconds the engine started. I let it run for a few seconds and then closed the bleed valve.

Alas, the same problem remains. The engine idles fine at just over 900 rpm for about 10 minutes then the rpms very slowly start to drop. If I apply some trottle then the rpms go up but after about a minute the rpms rapidly drop and it is time to shut it off before it quits.

I noticed when the engine was idling (before it died) that the fuel filter spins inside its clear housing. This seemed odd to me so I unscrewed the fuel filter housing and discovered there is no spring at the bottom of the housing to press the filter up. I have ordered one and hopefully that will fix the problem.