John Deere 6120 problem with injector. My name is John, the John Deere 6120 tractor is very useful in my business. But I have a problem with the injectors, I have not been able to solve the problem for a week, please tell me what is the problem?
As you know, any part of a tractor has its own resource, and diesel injectors are no exception. Even with the use of high-quality diesel fuel and timely replacement of filters, the sprayer and the nozzle as a whole will sooner or later fail. To a greater extent, this is due to extremely harsh working conditions – high temperature, high pressure.
Drop in the working pressure of the injection
The injection start pressure of the injector is adjusted to a specific value for each specific diesel engine model. During operation, the magnitude of this pressure inevitably decreases due to wear of the locking cone, the nozzle needle shank, the needle stop, the ends of the extreme turns of the nozzle spring, the stop of the adjusting screw or the package of adjusting washers, as well as the spring sag.
The tightness of the closing cone is broken
With a significant degree of wear of the closing cone, the tightness of the sprayer is lost, in this case it is often said that the sprayer is “pouring”. At the same time, the spraying deteriorates so much that instead of torches of foggy fuel, pronounced jets are observed. In this case, there can be no question of any normal mixture formation and combustion of fuel in the engine cylinder. There is also no clear end of injection, fuel leaks from the atomizer when the temperature and pressure in the cylinder are already significantly reduced.
Loss of tightness along the cylindrical guide of the sprayer needle
Although the needle-to-atomizer body pair is a precision product, there is still a gap in it, which is necessary to ensure normal movement of the needle. During the operation of the injector, a small amount of fuel leaks through this gap and is discharged through the “return” to the drainage system.