Case 1835C TMD20 Diesel - Won't run

I've been fighting this for some time. If I leave the skid loader sit for a day or so then it will start and run normal for about 45 seconds then it acts like it starves out of fuel and dies. It will then start for a few seconds then die, like the fuel shutoff is killing the fuel, but that's not the case. I've gone through the fuel lines and replaced the filter. With the filter off when I power the key to run fuel immediately runs from the feed side of the filter housing. There is good solid flow, but if I put my finger over the hole I'm able to stop the flow with little effort. Thinking this could mean the electronic fuel pump is weak I pressurized the fuel tank to ensure there was greater pressure and it doesn't change any symptoms. The skid loader seems to start easy, just won't run. Any thoughts would be greatly appreciated.

The fuel is bleeding off back into the tank. There are two things that can cause this.

1) Is an air leak on the supply side. It may not leak fuel but will leak air. That allows the fuel to run back into the tank.

2) I think there is a check valve in/on that motors injection pump. I am not sure exactly where it is. It is to keep the fuel from siphoning back into the tank.

Either of these will cause an air pocket in front of the injection pump. So the motor starts and then sucks the little bit of air in. Then when you check the system everything has fuel then. The air pocket has already been sucked into the pump.

This happening was real common on JD combines. They put a check valve right under the fuel filter on the back of the motor. The problem was that this is on TOP of the engine. About 4 feet about the fuel level if the tank is clear full, 6-7 feet in you have less fuel. The easy fix I found was to move the check valve down to the electric fuel pump. This was under the fuel tank. That stopped the trouble 90% of the time.

Any JD diesel combine from 1973 to 1988 had these check valves on them. You can get them off an junked one for a few bucks. Install one right at the tank on your skid steer.

Just happened to think of this. The electric pump on your skid steer could have this check valve made into it. It it has failed it would cause the problem you are describing. Maybe some of the other guys on here know about your fuel setup better.

One way to see if it is a bleed of issue. next time you are done with the skid steer. clamp the fuel line shut at the tank just after you run it. Then unclamp it the next time you start it and see if you still have your shut down issue. If you do not than you know the fuel is drain back into the tank.

Thanks for your insight. I"m not able to find any additional information on the check valve. There is a Manual for the motor I have on this here; http://www.wisconsinmotors.com:8080/wm/images/catalogs/continental/TMD_Operator_Repair_manual.pdf Not sure if this helps with any more insight than what"s been provided. I keep coming back to the fact that if I remove the filter and turn on the key I get good solid fuel flow, but if I put light pressure over the outlet I"m able to stop the fuel with very little effort. Shouldn"t there be some force (pressure) behind the fuel flow?

Thanks!

Thanks for your help - On the top of the injector pump is the fuel shutoff solenoid. From this is a Tee that brings return fuel from the injectors as well as overflow fuel from the pump back to the fuel tank. The Tee was clean, but the hole in the top cover (3 screws) was plugged. This was creating back pressure in the pump so it would starve. Cleaned the hole out and it runs great. Amazing how something so small and simple can cause total failure from the return side?

Edit - Or so I thought - ran great for about 3 minutes then died out again. This certainly points to this being the area.

Edit - Took it back apart and this time blew out the chamber with the air hose - put it back together and it's been running now for 10 minutes. Long enough for me to put the arms back down and get the bucket on anyhow. There may be something coming apart in there that is causing my issue, but only time will tell at this point.

Do you have a recommendation as to a source to rebuild the injector pump in the tmd20? I've been unable to find any information on this via the web in any form.

Thanks!