How Does the Fuel Pump Work?

The role of the fuel pump

In a diesel vehicle, the fuel pump is called a diesel fuel pump.  The fuel pump is located in the fuel tank. As mentioned above, its job is to take fuel from the tank and deliver it to the engine for injection. The car engine is an internal combustion engine. It works by mixing air with fuel.  The fuel is then injected into the combustion chamber and mixed with the air. In the past, fuel pumps were only used on diesel engines. Now, however, there's a pump on every car.

This pump also regulates the fuel pressure to deliver the right amount of fuel. This is made possible by the engine's ECU, which indicates the correct fuel pressure to be injected into the fuel system.

How a fuel pump works？

There are two types of fuel pumps: the electric fuel pump, found on modern vehicles, and the mechanical fuel pump, found on older vehicles.

How a mechanical fuel pump works

A mechanical pump is powered by the engine and uses a diaphragm to draw fuel from the tank. The diaphragm is connected to a lever that moves a plunger inside the pump. As the plunger moves up and down, it draws fuel through an inlet valve and into the pump chamber. The fuel is then pushed out of the pump chamber through an outlet valve and sent to the carburetor.

How an Electric Fuel Pump Works

The fuel pump is an essential component of a vehicle's fuel system, responsible for moving fuel from the tank to the engine. Its operation involves several complex stages and technologies

• Power supply: An electric fuel pump is typically located inside the fuel tank. It consists of a housing containing an electric motor and an impeller. The electric motor is activated by the ECU when the engine is started.

• Fuel suction: The fuel pump is connected to the fuel tank by a pipe or suction line. Inside the tank, it is usually equipped with a pre-filter to remove impurities and particles from the fuel. Once started, it begins to draw fuel from the tank.  Along the way, a propeller allows the fuel to bypass the pump's electric motor.

• Build pressure: One of the primary functions of the fuel pump is to pressurize the fuel to meet the combustion needs of the engine. Pressure is critical in the fuel system. Different engine types, such as direct or multipoint injection systems, require different fuel pressures. The design and operation of the fuel pump is aimed at providing the appropriate pressure to ensure proper engine operation.

• Fuel Distribution: Once compressed, the fuel is sent through the lines to the engine's fuel injectors. These injectors then spray the fuel in droplet form into the engine's combustion chamber as described above. These injectors are responsible for spraying the exact amount of fuel into each cylinder for combustion. This precise injection makes combustion more efficient and environmentally friendly.

• Electronic controls: Modern vehicles are often equipped with an electronic control unit (ECU) to manage and control the fuel pump. The ECU monitors engine demand based on data collected by sensors and adjusts fuel pump operation accordingly. This electronic control allows the fuel pump to match fuel flow to engine load, speed, and other parameters to improve fuel efficiency and engine performance.

The fuel pump also has a pressure regulator. It can also ensure proper fuel metering. In addition, the engine ECU activates a relay to drive the fuel pump. The fuel pump then injects more fuel than needed. The pressure regulator returns the excess fuel to the circuit, regulating its use.

How long do fuel pumps last?

Each fuel pump can last between 80,000 and 150,000 miles, or 5 to 10 years, depending on the vehicle model and how often you use it.

Overall, the fuel pump is a critical component of the fuel system. It delivers, sucks in, compresses, and distributes fuel to keep the engine running smoothly. Understanding how the fuel pump works is essential to understanding the operation and efficiency of a vehicle's fuel system.