In this article, you’ll learn what is fuel injection system? Its diagram, parts, working, advantages, and applications all are explained with pictures.
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A fuel injection system is a type of internal combustion engine system that uses fuel injectors to deliver fuel in a precise and controlled manner to the engine’s combustion chamber or cylinders. This ensures efficient combustion by atomizing fuel and injecting it under high pressure at the correct time into engine cylinders.
Carburetors were widely used on engines before fuel injectors were invented, and this engine is still in use today. In reality, many other machines still use carburetors, including lawnmowers and chainsaws. Due to the complexity of controlling all automobile requirements, fuel injection was released as a better alternative.
Fuel injection systems come in many different varieties, but they all share some basic parts. These parts include a fuel pump, a fuel injector, a fuel pressure regulator, and an electronic control unit (ECU) that manages the system’s operation.
Today’s vehicles use fuel injection systems to increase fuel efficiency, reduce emissions, and increase performance. In order to meet pollution standards and enhance engine performance, they also enable greater control over the air/fuel mixture.
The fuel tank serves as a reservoir for the fuel supply, helping to keep its temperature below the flash point. Additionally, the fuel tank plays a crucial role in dissipating heat from the fuel that is returned from the engine.
Fuel is transferred from the fuel tank to the fuel injectors by the fuel pump. Electric or mechanical fuel pumps are both available. The purpose of the fuel pump is to keep the fuel pressure constant.
The mechanism that injects fuel into a diesel engine’s cylinders is known as an injection pump. A toothed belt (often the timing belt) that also drives the camshaft is used to drive the injection pump indirectly from the crankshaft.
A fuel filter reduces the amount of dirt, debris, and other contaminants reaching the fuel injectors and helps prevent the fuel from becoming contaminated. A clogged fuel filter can reduce engine performance and even cause fuel injection system damage.
The governor’s function is to regulate the fuel to the engine cylinders in order to control the speed of the unit, holding the speed constant for all conditions of load forced on the generator being driven by the engine.
The function of the fuel pressure regulator is to control the fuel pressure and guarantee a steady flow of fuel to the engine. It helps to ensure that the fuel pressure stays within a predetermined range.
The parts that deliver the fuel to the engine’s combustion chamber are known as fuel injectors. Fuel is sprayed into the engine by the fuel injectors at high pressure and in a precise pattern.
A throttle body is a part of the engine that controls how much air is allowed to enter the engine. Normally, it’s situated halfway between the air filter and the intake manifold.
The fuel injection system’s ECM is referred to as its brain. The fuel and air mixture, fuel injection timing, and other parameters are adjusted by the ECM using input from various sensors to enhance engine performance and fuel economy.
An engine fuel injection system ensures efficient combustion and optimal performance by delivering fuel in a controlled and precise manner based on the engine’s operating conditions. Typically, it consists of an electronic control unit, a fuel pressure regulator, fuel injectors, and a fuel pump (ECU).
A fuel pump pressurizes the fuel and delivers it to the fuel injectors. Injectors deliver fuel to the combustion chamber of engines. The fuel pressure regulator keeps fuel pressure within a specific range, while the ECU analyzes engine load, RPM, and temperature to determine the best fuel delivery.
By modifying the fuel’s quantity, timing, and pattern of injection, the fuel injection system regulates the fuel’s delivery. As a result, the air-fuel mixture can be precisely controlled, ensuring efficient combustion and producing the best engine performance, fuel efficiency, and emissions reduction.
The type of system being used affects the specific function of the fuel injection system. For instance, a port fuel injection system delivers fuel to the intake port, while a direct injection system delivers fuel directly to the combustion chamber. Its overall purpose is to deliver fuel accurately and efficiently to the engine to optimize performance and efficiency.
The earliest fuel injection system to replace carburetors was the single-point type. Older cars frequently have this type of fuel injection system because it is the simplest. A single fuel injector is found on the throttle body, which is mounted on top of the intake manifold.
The throttle body receives the fuel spray from the injector, which mixes it with the incoming air before delivering it to the engine. It consists of one or two injector nozzles in the engine’s throttle body, which is the air intake manifold’s throat. While injectors are not as precise as carburetors, they have better control, are less expensive, and are easier to maintain.
Multiple fuel injectors are used in a multi-point fuel injection system, and they are positioned at the intake ports of each cylinder. This system enables better engine performance and more exact control over the fuel mixture.
This system uses multiple ports on each cylinder’s intake valve to inject fuel into internal combustion engines. It precisely and timely distributes the right amount of fuel to each cylinder. MPFI systems can be classified as Batched, Simultaneous, or Sequential. Modern automobiles and other vehicles frequently use it.
Instead of the intake manifold or throttle body, direct injection (DI) injects fuel directly into the engine’s combustion chamber. This system enables more exact control over the fuel mixture, which may enhance engine performance, increase fuel efficiency, and lower emissions.
These are typically managed by an electronic control unit (ECU) that determines the best fuel delivery using information from various sensors. Direct fuel delivery to the combustion chamber allows for optimizing the fuel mixture for various engine conditions, such as high load or low-speed operation.
In a sequential fuel injection system, fuel is delivered in a specific order to the engine’s cylinders based on the engine’s firing order. When the engine is idling, the fuel can stay for as long as 150 milliseconds because they all spray at the same time or in succession.
Sequential fuel injection has the advantage of allowing the engine to react more quickly to sudden driver changes. This is due to the fact that the valve doesn’t need to wait for the engine to turn completely; instead, it only needs to wait for the following intake valve to open.
The dual fuel injection system was developed to overcome the drawbacks of both port and direct injection systems. This system primarily relies on the port fuel injector at low RPMs because it produces a better air-fuel mixture. This assumes that the engine will benefit fully from port fuel injection.
As the RPM increases, the direct injector takes over, and the port injector shuts off. Since the direct injection system is quicker at higher RPM and may perform better, this improves combustion efficiency.
The port injector helps when the direct port injector cannot provide enough fuel at such high speeds as the RPM increases. At high RPMs, both injectors will work together to supply fuel to the cylinder.
Compared to conventional carbureted engines, fuel injection systems have a number of benefits.
While fuel injection engines have a number of benefits over conventional carbureted engines, there are also some potential drawbacks to be aware of.
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