What is the working principle of a car fuel injector?
2 Answers
Working principle of fuel injectors: 1. Most car fuel injectors are electromagnetic type, generally with a two-wire system consisting of a voltage wire and a ground wire. The ECU sends control voltage to the coil winding of the fuel injector, generating a magnetic field that lifts the needle valve, causing the injector to spray fuel. When the ECU stops supplying power, the needle valve closes under the action of the return spring, stopping fuel injection. 2. Electronic Fuel Injection (EFI): The EFI system in car engines generally consists of three main components: the fuel injection circuit, a sensor group, and an electronic control unit. If the injector is installed in the position originally occupied by the carburetor, meaning there is only one fuel injection point for the entire engine, this is called single-point injection. If injectors are installed on the intake pipe of each cylinder, meaning fuel is injected into the cylinders from multiple locations (at least one injection point per cylinder), this is called multi-point injection. 3. Direct Injection: The fuel injector is placed inside the cylinder, where fuel is atomized under high pressure and sprayed into the cylinder, then mixed with air for ignition.
I think the working principle of fuel injectors is pretty cool—they act like precise fuel attendants for car engines. The computer (ECU) calculates the required amount of fuel based on real-time data such as throttle pedal depth and engine speed, then sends an electrical signal to the fuel injector. Inside the injector, there's a small electromagnetic coil that generates a magnetic field when energized, pulling the needle valve open. High-pressure fuel then sprays out through the nozzle, forming fine mist-like particles. This ensures thorough mixing of fuel and air, leading to more efficient combustion, which enhances power while reducing exhaust pollution. If the injector gets dirty or clogged, uneven fuel spraying can cause engine shaking, sluggish acceleration, or increased fuel consumption. Therefore, it's important to use high-quality gasoline and clean the injectors regularly to keep the system running smoothly.
