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Teknikmobil.com – The injection pump is the main part of a diesel engine which provides a certain pressure required by the nozzle before it enters the combustion chamber. Correct timing, adequate pressure and pressure are two of the important requirements for an injection pump in a four-wheeled vehicle. In general, there are two types of fuel distribution before it enters the combustion chamber. For more details, below is a brief description of the problem.
Distribution-type diesel injection pump
NEEDS A HIGH-PRESSURE FUEL PUMP
A diesel engine injection pump is used to increase the diesel fuel pressure from very low values from the lift pump (please read: Combustion Phases and Diesel Engine Fuel Tanks ) to the very high pressure required for injection.
· The lift pump is a high pressure and high volume pump.
· High pressure injection pumps are low pressure pumps with low volume.
The injection pump is usually driven by a gear from the camshaft at the front of the engine. When the injection pump shaft rotates, diesel fuel is fed from the filling port to the high-pressure chamber. If a distributor type injection pump is used, fuel is forced out of the injection port into the correct injector nozzle through a high pressure line. See image above.
NOTE: Due to the very tight tolerances in diesel engines, even the smallest amount of dirt can cause excessive/major damage to the engine and fuel injection system.
DISTRIBUTOR INJECTION PUMP/DISTRIBUTOR INJECTION PUMP
The distributor diesel injection pump is a high-pressure pump assembly with lines leading to each injector. The high pressure line between the distributor and injector must be the same length to ensure proper injection timing. High pressure fuel causes the injector to open. Due to the internal friction of the lines, there is a slight delay before the fuel pressure opens the injector nozzle. The injection pump itself creates the advance injection necessary for engine speed using a stepper motor attached to the piston, and the fuel is then discharged into the lines. See image below.
Schematic of Standadyne diesel fuel–injection pump
NOTE: Lines expand during injection. This is how the timing check is done. Pulses from the injector line taken by the probe are used to detect injection events similar to the ignition timing used to detect sparks in gasoline engines.
HIGH-PRESSURE COMMON RAIL
Overview of computer-controlled high-pressure common rail V-8 diesel engine
Also read:
Kia Sportage Diesel Ready to Release in Malaysia
2018 Chevrolet Cruze Diesel Ready to Roll in America
Newer diesel engines use a fuel delivery system known as a High-Pressure Common Rail (HPCR) design. Diesel fuel under high pressure, over 20,000 PSI (138,000 kPa), is applied to the injectors, which are opened by a solenoid controlled by a computer. Because the injectors are computer controlled, the combustion process can be precisely controlled to provide maximum engine efficiency with the lowest possible noise and exhaust emissions. Look at the image above. [Halderman, 2012] Automotive Technology Principles, Diagnosis.[]