How fuel injection works animation picture

When the plunger rises, it opens a valve and the injector sends fuel through the spray tip and into either the intake manifold, just upstream of the intake valve, or directly into the cylinder. The system pumps more fuel than is needed for injection - a loop circuit returns the excess to the fuel tank via a pressure regulator which keeps the pressure in the pipes constant.

How Fuel Injection Systems Work

How Driver Drowsiness Detection system can help prevent the accidents? Learn More. A vacuum-powered fuel pressure regulator at the end of the fuel rail ensures that the fuel pressure in the rail remains constant relative to the intake pressure.

how fuel injection works animation picture

This design consists of an individual pump assigned to each cylinder rather than a common pump used for all cylinders in earlier generation models.

Let's talk about idling. The oxygen content in the exhaust provides an indication of how well the fuel is burning. All this information allows an electronic system to meter the fuel far more accurately than the simple mechanical system, which relies on sensing the airflow alone. These measure factors such as the air pressure and temperature in the air intake, the engine temperature, accelerator position and engine speed.

Filed to: It is then fed straight up pipes to the injectors. Mechanical fuel injection was used in the 1960s and 1970s by many manufacturers on their higher-performance sports cars and sports saloons.

how fuel injection works animation picture

All modeled in 3D We've created the most detailed 3D model ever produced so we can show you everything working. Club News. However, few automakers adopted it for mass-market cars.

Direct injection systems are more expensive to build because their components must be more rugged.

Direct Fuel Injection

The rotor is electrically connected to the ignition coil, which is basically a transformer that steps 12v up to over 10,000 volts needed for spark. Lower fuel consumption.

how fuel injection works animation picture

Virtually all diesel engines use direct fuel injection. When you initially turn on the vehicle, the ECU checks the engine temperature via a coolant temperature sensor. Repeatability of the movement of the valve 4. Modern vehicles don't use a centrally located ignition coil. The amount of fuel injected is controlled by a flap valve located in the engine's air intake.

Combined with ultra-precise computer management, direct injection allows more accurate control over fuel metering, which is the amount of fuel injected and injection timing, the exact point when the fuel is introduced into the cylinder.


It's more common to have single-point injection where a single injector feeds all the cylinders, or to have one injector to every two cylinders. A cross-sectional view of a conventional Diesel Injector diagram Working principle of a conventional fuel injector: Kinja is in read-only mode.

February 22nd, 2019 Shirish Deshpande. Conventional injectors open and close hydro-mechanically.