What are the components of a fuel injector?

[SanAsher]

Fuel injectors consist of three main parts: the fuel supply section, the air supply section, and the control section. As high-precision components with extremely tight manufacturing tolerances, fuel injectors require a wide dynamic flow range, strong resistance to clogging and contamination, as well as excellent atomization performance. They receive fuel injection pulse signals from the ECU to precisely control fuel injection quantities. The spray characteristics of fuel injectors include atomization particle size, fuel mist distribution, spray direction, injection distance, and diffusion cone angle. These characteristics must meet the requirements of diesel engine combustion systems to ensure proper mixture formation and complete combustion, thereby achieving higher power output and thermal efficiency. Electronically controlled fuel injectors are critical and complex components in common rail systems, representing components with significant design and manufacturing process challenges.

[McNoah]

The fuel injector mainly consists of several parts. There's an outer main housing that encloses the core components. First is the solenoid coil—when you start the ignition, a control signal arrives via wiring, energizing it to generate a magnetic field. Second is the needle valve or pintle, connected to a spring; once the coil is energized, the magnetic force lifts the needle valve, allowing fuel to flow out. At the tip are the injection nozzles, where high-pressure fuel is forced out, atomizing into fine droplets for more efficient engine combustion. There's also a filter screen installed at the inlet to trap impurities and prevent clogging. Sealing rings are essential to maintain an oil-tight system. The connector handles the wiring plug-in. With years of repair experience, I often see injector clogs causing engine misfires and increased fuel consumption—regular filter cleaning and using clean fuel can prevent this. Injector types include solenoid and piezoelectric, with the latter offering faster response but similar maintenance. Never overlook this small part—engine efficiency depends on it.

[SerenityAnn]

The fuel injector consists simply of a housing, coil, needle valve, injection hole, filter screen, and seals. The coil controls the opening and closing of the needle valve when energized. When the needle valve lifts, fuel is sprayed from the injection hole. The injection hole is designed to atomize the fuel effectively. The filter screen prevents impurities from entering the system. Seals such as O-rings prevent leaks. When the fuel injector fails, the car may experience difficulty starting or unstable operation due to inaccurate fuel delivery. During repairs, start by checking the filter screen—clean or replace it if dirty. Under normal conditions, fuel injectors operate reliably, but aging or poor fuel quality can shorten their lifespan. When I inspect them with tools, a multimeter should show a normal resistance value of 10-15 ohms. It is recommended to clean the fuel injectors every 20,000 kilometers, and fuel additives can be used for simple maintenance. Engine performance heavily depends on the precision of the fuel injector, so don’t skimp on maintenance costs.

[DiAdam]

The fuel injector structure is quite straightforward: the main body housing holds everything together, with an electrical coil inside that receives signals, a needle valve that moves to control fuel injection, small holes that spray atomized fuel, a filter screen at the front to block debris, and sealing rings to prevent leaks. When the coil is energized, it pulls the needle valve open, spraying fuel to keep the engine running. If the injector nozzles get clogged, the car will sputter. I work on modified cars and think upgrading fuel injectors can boost performance, but OEM parts are sufficient if well-maintained. Clean them when dirty—run a few tanks with specialized cleaner. Don’t underestimate fuel injectors; they’re small but crucial, affecting fuel efficiency and emissions. Regularly check the fuel filter to save hassle and money.