Combustion engines generate energy by burning a mixture of fuel and air. That said, an ideal ratio of air and fuel is required for proper combustion. Here comes the fuel injection system which is responsible for supplying the required amount of fuel to the combustion chamber. There are different types of injection systems but we will discuss direct fuel injection systems or gasoline direct injection systems (GDI).
Let’s elaborate on the direct fuel injection system, its working, components and advantages.
Direct Fuel Injection System
Direct fuel injection is a type of fuel injector that directly pumps fuel inside a cylinder. Whereas, the air is pumped separately from the manifold. Direct fuel injection is a relatively newer type of injection system which is more efficient and provides better fuel economy.
What Does Direct Fuel Injection Do?
As the name implies, the purpose of fuel injectors is to inject fuel to mix it with air and create a combustible mixture. This combustible mixture is ignited with the help of spark plugs, resulting in heat energy. The combustion pressure or energy generated pushes the piston downward rotating the crankshaft.
The usage of direct fuel injectors burns the mixture more efficiently resulting in more power generation and lesser emissions.
How it Works
The working of direct fuel injection systems involves a fuel tank, fuel rail, two fuel pumps (high pressure and low pressure) and a fuel injector.
The fuel is supplied from the fuel tank to the high-pressure pump through the low-pressure fuel pump. The high-pressure fuel pump is a mechanical pump which is operated by the camshaft.
It transports fuel to the fuel rail under high pressure. The fuel rail then distributes fuel to the fuel injectors present over the combustion chamber.
Now, the direct fuel injector inserts fuel inside the combustion chamber and the air is pumped through the intake manifold resulting in a combustion reaction. Pumping fuel directly into the chamber is the core difference between the direct injector and other types. In other types of fuel injectors, fuel and air are mixed outside the chamber which can affect the power generation capacity of the engine.
Pros and Cons of Direct Fuel Injection System
Here is the list of disadvantages and advantages of direct fuel injection systems in cars.
Pros
- Power Output: Direct injectors pump vaporised fuel particles with high pressure which catalyse the combustion process, thus increasing power output and fuel economy.
- Smooth Functioning: The high-pressure fuel pump and absence of a carburettor increase fuel flow resulting in the smooth functioning of the car.
- Improved Emissions: Carburetors increase carbon emissions at high speed. A direct fuel injector is exempted from this.
- Suitable for Alternative Fuels: Direct fuel injectors can function with alternative fuels and fuels with additives.
Cons
- Engine Noise: Fuel injection supplies fuel under high pressure which increases engine noise and turbulence.
- Malfunctioning: The small nozzle holes of direct injectors are more prone to blockage and malfunctioning.
- High Cost: Direct injectors are more constantly contrary to other types of injectors.
- Repair and Maintenance: Fuel pumps and direct injectors are complex auto parts that are difficult to repair and maintain.
Symptoms of Malfunctioning Direct Fuel Injection
Direct fuel injection systems can malfunction due to blockage of nozzles, the buildup of carbon, leakage in the fuel line or failing fuel pumps. Listed below are some common symptoms of malfunctioning fuel injectors.
- The engine is not reaching full RPM, rough performance and engine knocking may indicate a faulty fuel injector.
- Increased fuel consumption and fuel odour inside the car.
- Starting problems like car crank but won’t start or delayed ignition response.
- Increased carbon emissions and black, blue or white smoke from the tailpipe.
- Misfiring and frequent spark plug failures.
This was all about the direct fuel injection system. The system is considered because of efficient combustion, higher output and increased fuel economy. If you are interested in availing of these benefits, browse through these used cars for sale in the UAE and purchase a car with a direct fuel injector.
Stay tuned to UAE’s top auto blog for more information on direct fuel injection maintenance and repair.
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