Fuel must always enter the combustion cylinder to be compressed and then ignited. For many years, carburettors and fuel injectors dominated fuel delivery to the engine. Although fuel injectors are on their way to the future, carburettors have long been obsolete.
For four-wheeled vehicles, especially passenger cars, fuel injection has definitely prevailed. Still, carburettors have not completely disappeared from view and make for an interesting discussion about cars.
But first, let’s take a look at how the carburettor works and how it supplies fuel to the engine.
How Does The Carburettor Control Fuel Delivery?
The basic structure of a carburettor consists of a cylinder with an intake port at the top. Air enters the carburettor through this inlet port after being cleaned by an air filter. A mechanism (venturi, cone) throttles the airflow and increases its speed.
The nozzle releases fuel at the venturi opening, creating a mixture of air and fuel that enters the combustion chamber.
At the outlet of the carburettor, there is a valve (throttle) that regulates the airflow; its position determines the air supply to the carburettor, and the throttle is operated by the accelerator pedal. When the accelerator pedal is depressed, the throttle opens and airflow increases. As more fuel flows to the carburettor, the vehicle can burn more fuel.
When you release the gas pedal and the engine slows down, the airflow to the fuel mixture decreases.
How Does The Fuel Injection System Control Fuel Delivery?
The fuel injection system usually has a nozzle that is inserted into the combustion cylinders. The fuel passes through a pressure pump where it is atomized and mixed with air before being injected into the combustion cylinder.
However, the air supply is controlled by an air sensor. Similarly, the fuel supply is controlled by instructions from the fuel sensor. There are other sensors that measure engine load, temperature, and throttle position, but all of these sensors send data to the ECU, where fuel delivery is determined by a series of calculations.
Why Do Fuel Injection Systems Replace Carburettors?
Almost all modern vehicles, especially those manufactured since the turn of the millennium, are now equipped with fuel injection. What makes this subtle change necessary? Yes, of course! Why should cars be left behind when the world is moving to computer technology?
Carburettors are more of a manual injection system, with no ECU or sensors intervening.
Fuel injection systems, on the other hand, rely on an electronic control unit (ECU) to control most of the engine’s functions. The electronic control unit makes highly accurate fuel delivery decisions based on a range of data that comes from multiple sensors, such as airflow, throttle position, engine speed and more. All of the data is processed by the ECU, which then determines how much fuel to add. This is how the system determines fuel delivery, making fuel injection an efficient system that works on demand. The efficiency of the fuel injection system allows the vehicle to start smoothly even in the most difficult conditions, such as very cold days.
Nowadays, vehicles equipped with carburetors are mostly two-wheelers. When you need to start a two-wheeler, the choke comes into play. Once the choke is pulled, the vehicle can start. After that, the vehicle has to warm up properly before it can continue.
With a Carburetor, the same effort is required to start a four-wheeled car on a cold day. You have to operate the choke and let the engine warm up before you can continue. With fuel injection, this effort is eliminated.
Also, carburetors are not the best choice in terms of fuel efficiency, as proper fuel delivery prevents fuel waste. However, there are many vehicles that prefer carburetors, especially the much-improved version known as direct injection.
There are also regions where there is a demand for vehicles with carburetors, and somehow, they are also supplied with these vehicles. Usually, the vehicles are purchased from the original manufacturer before changes are made to them, such as the elimination of computerized controls and the use of more mechanical devices such as carburetors. The main reason for these changes is to reduce the final cost of the vehicle.
Is Fuel Injection More Difficult To Maintain Than A Carburettor?
A carburetor is more of a mechanical device; therefore, repairing a carburetor requires hand tools and a willingness to get your hands dirty; however, repairing an engine does not come without the appropriate technical knowledge.
The fuel injection system is a complex system that relies on electronic sensors and computers, and it takes a professional to repair it. However, with automatic scanners and diagnostic equipment, you can easily identify the problem by simply plugging in a wire.
If you have a problem under the hood, Gargash Auto’s trained experts are always on hand to troubleshoot and find the right solution.