page_title: Component parts of internal combustion engines
section_title: Fuel systems
hierarchical_section_title: Component parts of internal combustion engines / Ignition system / Fuel systems
caption_attribution_description: English: An animated cut away diagram of a typical fuel injector. Fuel injectors are used to spray controlled amounts of fuel into an internal combustion engine. A solenoid is activated when fuel is intended to be delivered to the engine, causing the plunger to become pulled toward the solenoid by magnetic force. This uncovers the valve opening, allowing fuel to flow into the atomiser and out the spray tip, as it is under pressure. A valve spring attached to the plunger returns the plunger to its original position when the solenoid is switched off. The route of fuel is shown in orange; grey/blue indicates no fuel present.
context_page_description: Internal combustion engines come in a wide variety of types, but have certain family resemblances, and thus share many common types of components.
context_section_description: Fuels burn faster and more efficiently when they present a large surface area to the oxygen in air. Liquid fuels must be atomized to create a fuel-air mixture, traditionally this was done with a carburetor in petrol engines and with fuel injection in diesel engines. Most modern petrol engines now use fuel injection too — though the technology is quite different. While diesel must be injected at an exact point in that engine cycle, no such precision is needed in a petrol engine. However, the lack of lubricity in petrol means that the injectors themselves must be more sophisticated.
caption: Animated cut through diagram of a typical fuel injector, a device used to deliver fuel to the internal combustion engine.