How Does an Automotive Fuel Injector Work?
2 Answers
Automotive fuel injector works as follows: High-pressure fuel is pumped into the injector through the fuel supply port. The high pressure generated inside the injector body acts on the nozzle cone surface. When the fuel pressure exceeds the set value, the nozzle valve core opens, allowing high-pressure fuel to spray out from the small nozzle holes in a mist form into the engine cylinder for combustion, driving the piston's reciprocating motion. An automotive fuel injector consists of the injector body, nozzle, support seat, and spring. Its classifications include: 1. Pintle-type electromagnetic fuel injector; 2. Ball-type electromagnetic fuel injector; 3. Plate-type electromagnetic fuel injector; 4. Bottom-feed fuel injector. The function of an automotive fuel injector is to inject fuel into the intake manifold or cylinder according to the injection timing and pulse width calculated by the engine ECU.
I frequently repair cars and have seen many issues with fuel injectors. Their working principle is quite simple: the engine's brain, called the ECU, calculates how much fuel to inject based on sensor data like vehicle speed and temperature, then sends an electrical signal to the fuel injector. Inside the injector, a tiny valve opens briefly, allowing high-pressure gasoline to spray out, instantly atomizing into fine droplets that mix with air and ignite for combustion. If atomization is poor, incomplete combustion occurs, leading to black smoke from the exhaust and increased fuel consumption. From my repair experience, fuel injectors are prone to clogging, especially when using low-quality fuel or leaving the car unused for long periods. Sludge buildup narrows the injector nozzles, requiring cleaning or replacement. Regular maintenance and using high-quality fuel can significantly extend their lifespan and improve driving smoothness.