Fuel system schematics are diagrams that are used to illustrate the fuel delivery system on a vehicle. These particular types of diagrams can be found in special books called repair manuals, which contain information about all of the systems in a vehicle.
A fuel system schematic shows all the components involved in pushing gasoline throughout the engine. On older vehicles, this would include the carburetor, fuel lines and fuel cell. Complete fuel system schematics also include the pump located inside of a gas tank and the lines that route into the engine. Newer vehicles also include diagrams which show fuel injected systems.