rough running 5105

[daRedbone]

'05 JD 5105 started running rough, rpm cycling up and down about 100 rpm at lower rpm. A few minutes later it died and wouldn't restart. A few hours later it started but only at wide open throttle. It will a steady 2400 rpm but begins to run rough as I lower the rpm. I can hear it even at 2300 rpm. The cycling gets worse as I slow it down. It cycles about 100 rpm at 1500 and won't idle for even a minute. That wouldn't sound like a fuel supply problem to me but I checked first filter in line and it is perfect. I checked the second one for water - nothing. I broke the suction line to pump - nothing but fuel. I pulled the line off one of the injectors and turned engine over - it spit fuel. I'm in over my head now.

 

[jd110]

Sounds like it might be a problem in the governor inside the injection pump. It might be wort a try to change the filter and add some fuel conditioner/cleaner. Does the tractor run very frequently, or does it sit for extended periods? How old is the fuel in the tractor? If older than 6 months, I would drain it and add fresh fuel.

 

[daRedbone]

The fuel is fresh. It is used 2-3 times a week, usually not for long but pretty often. I think I'll change filters and add some fuel conditioner/cleaner but I'm leaning toward this being a pump problem. Running good at W.O.T. and bad as rpm is lowered kinda rules out fuel supply problem.

 

[daRedbone]

FYI, it starts and runs better after installing a new air filter but still runs kinda rough..

 

[kioskcarp]

check the screen in the tank to the line if it has one. My 5045 had the same problem in the winter gelling up the screen.

 

[JD5210]

Looking at JDparts there is a strainer/filter part number RE220719, back by the fuel tank.

John Deere - Parts Catalog

 

[daRedbone]

I'm finally getting around to reporting fix to problem. John Deere left the fuel filter gasket out. I put a gasket in the filter and it runs perfectly now. Sucking air into the fuel supply will do it every time.