Where is a typical automotive fuel pump located and what does it do?

• A. Inside the engine intake, drawing fuel from a separate reservoir.
• B. Inside the fuel tank; it pumps fuel to the fuel rail at the regulated pressure.
• C. It resides in the engine block to boost the fuel pressure.
• D. It attaches to the throttle body to meter fuel flow.

Answer: (B)

The main idea is that the fuel pump in most cars lives inside the fuel tank and its job is to push fuel from the tank up to the fuel rail at a regulated pressure. Being submerged in fuel helps keep the pump cool and prime, while the fuel rail and a pressure regulator make sure the injectors receive fuel at the right pressure for efficient spraying. If the pump were placed in the intake, engine block, or throttle body, it wouldn’t reliably deliver or regulate fuel for the injectors in modern electronic systems, which is why those locations aren’t correct.