John Deere 6120 Fuel System Problem. My John Deere 6120 has only done 2000 hours and is suffering from a fuel problem that I’m still getting to the bottom of. I have replaced all the fuel lines on the suction side of the injection pump, as well as both filters, but I am getting air into the system. After about 10 minutes at 2100 RPM it starts to “hunt” and fume as the rpm drops to 1100 RPM or so at full throttle. I stop the tractor, bleed the system and the air is present, where could this come from? I am thinking that the water separator filter housing may be faulty or the small in-line priming pump. Has anyone in the tractor world had this problem?
The problems of the fuel system are basically the following:
- Appearance of greater or strange noises during the operation of the engine;
- Decrease in power and engine speed;
- Difficulty starting the engine;
- Increased fuel consumption.
A key factor for the proper functioning of the fuel system is its quality, the impurities of which can cause significant damage. The consequence of contamination can be unscheduled replacement of components, parts, up to a thorough overhaul of the fuel system. The correct choice of consumables, particularly fuel filters, is also important. Repair is a last resort, sometimes adjustment is enough to fix the problem. Diesel fuel system tuning is a complex process that requires a high qualification of a mechanic.
It is also possible to repair the pump injectors.The quality of the repair of the pump injectors depends on the correct diagnosis. Diagnosis of a diesel engine should be carried out not only when equipment failure is evident, but also when there are even the smallest signs of changes in the John Deere fuel system operation. Therefore, if we are talking about the work of injectors, injection pumps, pump injectors, timely diagnosis will allow you to identify a malfunction at the earliest stage, respectively, the repair will require minimal time and financial costs. Qualified repair of John Deere unit injectors includes repair work to eliminate injectors malfunctions and replace parts with new ones, calibrate the fuel system, diagnose at the booth with the programming of a new code pump injector.