Importance of fuel injection system and how does it work?

The performance of a diesel engine is mostly determined by its fuel injection system. In reality, improvements in fuel injection systems might lead to improved engine performance.

The primary function of a fuel injection system or pump is to supply fuel to the cylinders of a diesel engine, but the mechanism of delivering the gasoline has an influence on engine performance, emissions, and noise. Let us investigate this mechanism, which influences so many distinguishing elements of an engine.

A fuel injection pump’s functions;

A diesel engine, unlike its petrol version, requires fuel to be supplied under high pressure. The system components must be able to resist severe pressures to do this.

  1. The fuel injection system, in general, guarantees that the fuel is injected at the correct moment and that the timing is regulated.

2. It also regulates the amount of gasoline fed to the engine, ensuring that it has enough power.

 Some factors that contribute to the fuel injection system’s peak performance are:

Fuel atomization

Atomization is the process of breaking down into smaller bits. Fuel injection must split the fuel into small bits so that it completely evaporates while maintaining high efficiency. If the gasoline is not broken down into tiny bits, it will not completely vaporise, resulting in low engine performance and an increase in vehicle operating costs.

Bulk mixing

We know that oxygen is required for optimal combustion. As the oxygen is combined, this is referred to as bulk mixing. If there is insufficient oxygen available during the burning of the fuel, the efficiency will be reduced. For the engine to perform properly, sufficient oxygen must be continually entrained into the fuel stream during the combustion process.

Air utilization

This has something to do with bulk mixing. A suitable amount of air must be used by the fuel injection pump. The air input is separated into a number of jets for this reason, and it is ensured that the fuel receives as much air as possible during the combustion process.

The primary functions of a fuel injection system.

Fuel injector parts and description

While delving into the components of a fuel injector, it is important to understand that the fuel injection system is divided into two parts: low pressure and high pressure.

The low pressure side comprises three components: a gasoline tank, a fuel supply pump, and a fuel filter, whereas the high pressure side features a high pressure pump, an accumulator, a fuel injector, and a fuel injector nozzle.

 A summary of the low pressure side components

Obviously, the fuel injection system requires gasoline to be supplied to it from the fuel tank in order to function. This is done via the low pressure side.

The gasoline tank as well as the fuel supply pump

The fuel tank serves as a fuel reservoir. Gasoline tanks must be anti-corrosive and leakproof to prevent fuel leaks. Fuel tanks must also be able to sustain pressures more than 30kPa. A fuel tank keeps the gasoline temperature below its flash point. It also serves to disperse heat from the engine.

The fuel supply pump transports fuel from the fuel tank to the high pressure pump. The engine can power fuel supply pumps either electrically or manually. It is possible to deploy electronic gasoline delivery pumps everywhere, including within the tank. Mechanical supply pumps can be used for more than just their regular function, such as a fuel pump and a vacuum pump for a brake booster.

Fuel filter

Since gasoline may include pollutants, a fuel filter is required for the engine to perform properly. It may have one or more filtering stages.

A two stage filter normally has a primary filter installed on the input side of the fuel transfer pump. It removes the bigger pollutants.

Since gasoline might include pollutants, a fuel filter is required for the engine to perform properly. It may have one or more filtering steps.

Synthetic fibres or cellulose are common materials used in contemporary filters to filter out particles. Micro glass membranes can also be utilised, although they are not recommended owing to the danger of harming fuel supply components if one of them breaks off.

When two stage filtration is employed and the primary and secondary layers are in sequence, the primary filtration eliminates particles 10-30 micrometres in size and the secondary layer  filters out particles 2-10 micrometres in size.

Aside from pollutants, the filtration system includes components for filtering out water, as water can cause major damage to numerous components. An excellent strategy is to create a filter medium that separates water from fuel.

Components with a high pressure side

The fuel is transferred from the low pressure side to the high pressure side for the final processes.

 High pressure pump

This machine transports gasoline from the low to the high pressure side. A volume controller is installed on the suction side and is controlled by a metering unit. This is in charge of supplying the needed amount of gasoline to the pump.


This functions to increase the amount of fluid in the system. This component in the fuel-injected system maintains a consistent pressure and dampens pressure fluctuation during fuel injection during combustion.

Fuel injector

A fuel injector is a valve that is operated electronically. The fuel pump delivers pressurised gasoline to this valve, which opens when the instruction is given. It may open and close several times in a single second.

Fuel injector nozzle

In layman’s terms, it is the tip of the fuel injector. The fuel is expelled through this nozzle.

Fuel supply system of petrol engines

The carburetor system is frequently used in gasoline engines. To ignite the gasoline, a spark plug is needed. Carburetors are less efficient than fuel-injected engines.

A carburetor draws fuel straight from the tank, therefore it is uncontrolled and consumes a lot of fuel.

However, bikes have improved, and fuel injection technologies are now employed in petrol engines as well. The fuel injection system controls and distributes gasoline through the injector. As a result, fuel-injected motorcycles are more efficient and get greater mileage.

To summarise, the fuel-injected system is a very advanced mechanism about which we have learnt a great deal in this study. Knowing how your car’s engine works and which system is more efficient will assist you in making selections.

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