The Requirement Of High Injection Pump Design

  •   The vast majority of modern cars are equipped with fuel injection systems. There are modifications in which gasoline is sprayed with a nozzle in the intake manifold. There are also models in which fuel is sprayed directly into the engine cylinders.

      Diesel engines work differently from gasoline engines. In them, the diesel is fed into the already compressed medium in the cylinder. In order for a portion of fuel to be atomized without hindrance, a mechanism such as a High Pressure Injection Pump is needed.

      Consider the features of such a mechanism, its modifications and signs of malfunction.

      What Is A High Pressure Fuel Pump And What Is It For?

      The mechanism, which is abbreviated as a fuel pump, is part of the fuel system of a diesel engine, but there are also models for gasoline power units. The only difference between the fuel pump of a diesel engine is that the pressure it generates is much higher than its gasoline counterpart. The reason for this is the fundamental features of the unit's operation. In the cylinders of a diesel engine, air is first compressed to such an extent that it heats up to the ignition temperature of the fuel.

      When the piston reaches top dead center, the nozzle sprays fuel and it ignites. The injector has to overcome enormous pressure. For the system to work properly, the pump must create a higher head than in the cylinders.

      In addition to the mentioned function, the pump must also supply fuel in portions, depending on the operating mode of the power unit. This parameter is determined taking into account the rotation of the crankshaft. In a modern car, this process is controlled by an electronic control unit.

      Since the first gasoline engines were equipped with carburetors, only diesel units needed such a mechanism. Nowadays, gasoline engines with a direct injection system also have a pump of this type (the carburetor is already extremely rare - only in older generation cars).

      Although the principle of operation of the pump has remained practically unchanged, the mechanism itself has undergone multiple upgrades and improvements. The reason for this is an increase in the environmental standards and performance of the internal combustion engine. Initially, a mechanical injection pump was used, but it was not economical, which led to volumetric emissions of harmful substances. Modern electronic pumps show excellent efficiency, which allows transport to fit into the framework of environmental standards and satisfy modest drivers.


      There is a wide variety of modifications of the fuel injection pump for a gasoline engine, as well as a diesel analogue. However, in most cases, the main elements of a mechanical pump are:

      A filter is installed at the inlet in front of the pump;

      A plunger piston located in a cylinder - the so-called. plunger pair;

      The body in which the recesses are made - through them fuel is supplied to the plunger pair;

      Shaft with cam and centrifugal clutch. This element is connected to the timing pulley using a belt drive;

      Plunger pair drive pushers;

      Springs that return the plunger piston back;

      Blower valves;

      Regulator of modes - associated with the gas pedal;

      Injection Pump Machine return valve (through it, excess fuel is fed into the return);

    Low pressure pump (pumps fuel into the pump).

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