Fuel System Components and Functions

Fuel System: Main Ideas

The fuel system stores and delivers gasoline or diesel to an internal-combustion engine. The video compares it to the body’s circulatory system: the fuel pump acts like the heart, the fuel lines like veins, and the filter like the kidneys. A failure in any of these parts can disrupt engine operation.

The video notes that an engine needs air, fuel, and a spark to run.

Main Components

Fuel Tank

• Stores fuel, which enters through a filler pipe.
• A level sensor reports the amount of fuel to the dashboard gauge.
• Modern tanks may also contain the fuel pump and systems that limit fuel-vapor emissions.

Fuel Pump

• Moves fuel from the tank toward the engine.
• In newer cars, it is usually located inside the tank. In older vehicles, it may be mounted on the engine or on the frame between the tank and engine.
• Electric pumps are powered by the car battery. Engine-mounted pumps use mechanical power, often from the camshaft and sometimes from the crankshaft.

Fuel Lines

Fuel lines carry fuel between the tank, pump, and engine components. For diesel engines, the video describes three types:

• Heavy lines: Carry high-pressure fuel between the pump and injectors.
• Medium lines: Carry fuel at moderate pressure between the tank and pump.
• Light lines: Serve areas with no or minimal pressure.

Fuel Filter

• Removes contaminants that could harm engine performance or durability.
• Filtering is important because the small openings in injectors and carburetors can clog easily.
• Filters may be placed before or after the pump, and sometimes in both locations.
• Common materials include paper, stainless steel, and synthetic materials. Most filters are disposable, though some sports-car filters use washable mesh.

Fuel Injectors

• Replace the carburetor’s role of mixing fuel and air, with a computer controlling when and how much fuel is delivered.
• Each injector is described as a small electric valve that opens and closes in response to an electrical signal.
• Injecting fuel near the cylinder head helps keep it in fine, atomized particles for better burning when ignited by a spark plug.
• The video says fuel injection has contributed to lower emissions and improved fuel economy. It became common in domestic cars after 1986 and in earlier foreign cars.

Carburetors

• Mix fuel and air without computer control.
• Are relatively easy to operate but often require adjustment and repair.
• Newer cars moved away from carburetors in favor of fuel injection, according to the video.

Speaker and Source

• Speaker: One unnamed narrator.
• Video source: Automotive Explained.