I am going to post here as the combine forum is probably slowing down some. I wanted to move my Deere 6620 to another farm so I could make repairs on the rear axle last week. It will start but only run for 3 or 4 minutes. Then you open the air bleeder bolt on the fuel filters and pump the plunger on the injection pump removing all of the air and filling the filters and it will start and run another 3 or 4 minutes. Did that process a couple of times and still get the same 3 or 4 minutes of run time before it starts missing, looses rpm and dies. Was running perfect when I quit using it in the field three four weeks ago. Fuel filters would have around 75 hours on them. Electric pump on tank has never caused problems and you can hear it work. Tried to run it last week on Saturday when it was 40 degrees, same problem. Engine compartment may not have warmed up to 40 degrees. Does have 10% biodiesel in the tank. Do I have some frozen water in the filters?? Would the filters plug in 75 hours?? If the filters were plugged or iced would doing the plunger on the injection pump actually solve plugged fuel filters?? I did drain the water trap on the fuel tank and only diesel came out. Screen in the sediment bulb on the tank is clean. I have full flow from the sediment bulb out the bottom of the tank. Do I have some chaff floating up and down in the fuel line from the tank?? Wanted to get it moved before winter really sets in. Any ideas?? Thanks.