fuel problem

[Walkin Horse]

I would check the fuel tank before I went tearing into an injector pump. I just think if it runs at all the pump is good. Even if the primer pump goes bad the diaphragm stops up the and it won't run at all.

Ever heard of anybody calling an electrician and he turned the breaker back on. Sometimes simple does it.

 

[Tx Jim]

thanks Tx Jim I will try that tomorrow. Just one question, is the gasket/cover on the side of the IP that faces out or is it facing toward the block? its kind of hard to tell from the diagram.

Cover will be facing away from engine.

 

[Oiltech]

I have a JD 410C backhoe that seems to have a fuel flow problem. I tried to start it and even though it was cold it seemed to take longer than usual to start, when it finally started it idled around 1,000 RPM and ran fine but it would not throttle up (even at full throttle it stayed at idle) I then shut the machine off and checked the throttle linkages and found no problems. I came back to the machine a few days later and started it again it was running on all cylinders but was surging between 500-600 RPMs then it stalled (start it again and it would do the same- then stall in a few seconds) My question is how would I tell if the lift pump was bad or if the injection pump was the problem? the lift pumps looks like it has been replaced recently but I have not replaced it so I don't know for sure. also the fuel filter has been changed

I experienced the same problem as you, apparently a rodent made a nest in my fuel hose when it was laying on the ground. The next time I filled up this made its way inside the fuel tank and was plugging the outlet.

 

[chrisdvorak]

ok here is what I have done.
-drained tank (fuel did not look bad nor did i find any junk)
-removed fuel lines and blew them out with compressed air
-changed fuel filter
-replaced fuel lift pump
And i am still having the same problem, starts right up and then dies. This is now driving me crazy. I figure I must be overlooking something but have no idea what it is?

 

[Qapla]

Are the fuel lines metal or flexible? If flex, when you blew them out, did you blow them from both ends? It may sound odd, but a rubber flex line can get a "tear" inside that will act like a "flap" closing off the line when liquid runs in one direction even though it flows just fine in the other direction.

Also, make sure you do not have any pinholes in a line that has suction - not pressure - on it. A pinhole in a suction line will not leak fuel but it will allow air into the injectors.

 

[chrisdvorak]

all the lines are metal, there are only 2 rubber lines. the line coming from the tank to the lift pump which is gravity fed and it flows freely, and a small 6" line that goes from the metal leakoff line for the injectors to the tank.

 

[Tx Jim]

ok here is what I have done.
-drained tank (fuel did not look bad nor did i find any junk)
-removed fuel lines and blew them out with compressed air
-changed fuel filter
-replaced fuel lift pump
And i am still having the same problem, starts right up and then dies. This is now driving me crazy. I figure I must be overlooking something but have no idea what it is?

DID YOU LOOSEN THE 2 SCREWS ON THE TIMING COVER on the IP AS I SUGGESTED????????????

 

[chrisdvorak]

not yet, I started at the fuel tank and am working my way down through the system. I will try first thing in the morning.

 

[chrisdvorak]

Thanks Tx Jim I think I finally got it figured out, ended up being a blocked check valve in the return line of the injection pump.

 

[Tx Jim]

That's what I guessed that's the reason to loosen timing cover to see if engine would then run correctly. I'm glad you got figured out.