Fuel Systems & Fuel Delivery Flashcards

What is the primary function of a fuel pressure regulator in a fuel injection system?

Answer: To maintain consistent fuel pressure in the fuel rail

The fuel pressure regulator maintains a consistent pressure in the fuel rail regardless of engine demand, ensuring proper fuel delivery to the injectors.

What type of fuel pump is typically used in modern fuel-injected vehicles?

Answer: Electric in-tank pump

Modern fuel-injected vehicles use electric in-tank pumps because they provide consistent high pressure and are cooled by the surrounding fuel.

What is the typical operating fuel pressure for a port fuel injection (PFI) system?

Answer: 35–65 PSI

Port fuel injection systems operate at 35–65 PSI to properly atomize fuel into a fine mist for efficient combustion.

Which component in the fuel system prevents fuel vapor from escaping into the atmosphere?

Answer: EVAP canister (charcoal canister)

The EVAP canister absorbs and stores fuel vapors until the purge valve opens and routes them to be burned in the engine.

At what mileage interval should a conventional inline fuel filter typically be replaced?

Answer: Every 30,000–60,000 miles

Most manufacturers recommend replacing the inline fuel filter every 30,000–60,000 miles to maintain adequate fuel flow and protect the injectors.

What is the purpose of a fuel pulsation damper (pressure damper) on the fuel rail?

Answer: To reduce pressure fluctuations caused by rapid injector firing

A fuel pulsation damper absorbs pressure spikes that occur each time an injector opens and closes, smoothing fuel delivery for more consistent performance.

What is the most likely result of a clogged fuel injector?

Answer: A lean condition and potential engine misfire

A clogged injector delivers less fuel than commanded, creating a lean air/fuel mixture in that cylinder which can cause misfires and rough running.