What is the working principle of fuel injection by the fuel injector?
3 Answers
The working principle of fuel injection by the fuel injector is: high-pressure fuel is pumped into the fuel injector through the fuel supply port, and the high pressure generated inside the injector body acts on the conical surface of the fuel injector. When the fuel pressure exceeds the set value, the injector valve core opens, and high-pressure fuel is sprayed out from the small holes of the nozzle in a mist form into the engine cylinder for combustion, causing the piston to reciprocate. The fault phenomena and solutions of the fuel injector are: 1. Nozzle blockage: Use chromium oxide applied on a flat plate for grinding; if the cylindrical surface of the needle valve is severely worn, it should be replaced in time. 2. Poor sealing: Apply chromium oxide or toothpaste on the sealing band at the end of the needle valve. 3. Piston wear: Replace the piston.
Having worked in the auto repair industry for many years, I'm very familiar with how fuel injectors operate. When you start the car engine, sensors detect data like air flow and throttle position, transmitting it to the Engine Control Unit (ECU). The ECU then calculates and sends electrical pulse signals to the fuel injector. When energized, the internal coil generates magnetic force, lifting a small needle valve to allow high-pressure gasoline to spray through the nozzle, forming fine mist droplets. These atomized droplets mix with air in the intake manifold or directly enter the combustion chamber, where they're ignited by the spark plug for combustion. This atomization process ensures complete fuel combustion, improving efficiency while reducing emissions and preventing engine hesitation or excessive fuel consumption. If a fuel injector becomes clogged or worn, it can cause uneven fuel delivery, affecting performance—regular cleaning with fuel additives is recommended. Modern vehicles use multi-point injection systems with individual cylinder control, ensuring smooth cold starts and quick acceleration response. Proper maintenance can significantly extend engine life.
As a car owner, I pay attention to the fuel injector's operation because it directly affects the vehicle's fuel consumption and power. When stepping on the accelerator, the car's computer ECU responds quickly, sending signals to the fuel injector, which opens its valve to spray gasoline under high pressure into a fine mist. This atomization allows gasoline to perfectly mix with air, resulting in cleaner and more powerful combustion. My old car once felt sluggish due to carbon buildup in the fuel injector, but it improved significantly after cleaning. Fuel injectors are typically located near the engine's intake system and rely on electronic control switches to achieve millisecond-level precise injection, adapting to idle or rapid acceleration conditions. If impurities clog the injector nozzle, atomization deteriorates, leading to black smoke from the exhaust pipe or difficulty starting. It's important to replace the fuel filter on time to avoid such issues. This design is far more efficient than the old carburetor system—better atomization means improved fuel economy and environmental friendliness, especially providing stable performance at high speeds.
