What does an injector do?

What is a fuel injector?

A fuel injector is a device that atomizes and injects fuel into an internal combustion engine. The injectors atomize the fuel and push it directly into the combustion chamber at precise points in the combustion cycle. Newer injectors can also meter fuel as directed and controlled by the Electronic Control Module (ECM). Gasoline fuel injectors are now used as a replacement for carburetors, where the air-fuel mixture is drawn in by the vacuum created by the downward stroke of the piston.

Why do we need injectors?

Fuel injectors are necessary engine components because:

· The working principle of the internal combustion engine determines that the better the quality of the fuel-air mixture, the better the combustion, which provides higher engine efficiency and lower emissions.

· The inefficient air-fuel mix provided by the carburetor leaves a variety of unburned particles in the combustion chamber of the internal combustion engine. This leads to improper propagation of the combustion flame due to a malfunction known as "knock" as well as higher emissions.

· Unburned fuel in the form of carbon or unburned gases and particles in the combustion chamber can negatively impact the vehicle's efficiency (mileage) and emissions. To avoid this, upgrading fuel injection technology has become crucial.

Types of Fuel Injectors

Advances in fuel injection technology have resulted in various fuel injection arrangements such as throttle body fuel injection, multi-point fuel injection, sequential fuel injection, and direct injection, with these arrangements varying according to the application.

There are two types of injectors:

1. Diesel injector

Modern diesel injectors are used to atomize diesel (a fuel heavier than gasoline) directly or into the combustion chamber of a diesel engine for compression ignition (without a spark plug).

Diesel fuel injectors require much higher injection pressures (up to 30,000 psi) than gasoline injectors because diesel is heavier than gasoline and higher pressures are required to atomize the fuel.

2. Gasoline injector

Gasoline injectors are used to inject or inject gasoline directly (GDI) or through the intake manifold (multiport) or throttle body into the combustion chamber for combustion, the combustion being ignited by a spark.

Fuel Metering Basics - Fuel Injectors

There are two types of fuel metering (controlling the duration, pressure and timing of the injected amount of fuel) fuel injectors.

1. Mechanically controlled fuel injectors

Mechanical fuel injectors in which fuel velocity, quantity, timing and pressure are mechanically controlled using a spring and plunger. These components take input from cams or injection pumps.

2. Electronic fuel injector

These injectors are electronically controlled in terms of fuel volume, pressure and timing. The electronic solenoid accepts input from the vehicle's Electronic Control Module (ECM).