NAPA Fuel Systems & Fuel Delivery

Question 1

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

Accepted Answer

To maintain consistent fuel pressure in the fuel rail

Answer

To filter contaminants from the fuel

Answer

To measure fuel flow to the injectors

Answer

To control the fuel pump speed

Question 2

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

Accepted Answer

Electric in-tank pump

Answer

Mechanical diaphragm pump

Answer

Gear-driven camshaft pump

Answer

Rotary vane external pump

Question 3

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

Accepted Answer

35–65 PSI

Answer

5–10 PSI

Answer

15–20 PSI

Answer

100–150 PSI

Question 4

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

Accepted Answer

EVAP canister (charcoal canister)

Answer

Fuel pressure regulator

Answer

Inline fuel filter

Answer

Fuel rail check valve

Question 5

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

Accepted Answer

Every 30,000–60,000 miles

Answer

Every 3,000 miles

Answer

Every 10,000–15,000 miles

Answer

Only when fuel flow is restricted

Question 6

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

Accepted Answer

To reduce pressure fluctuations caused by rapid injector firing

Answer

To increase fuel pressure to the injectors

Answer

To prevent fuel from flowing backward into the tank

Answer

To regulate fuel temperature entering the rail

Question 7

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

Accepted Answer

A lean condition and potential engine misfire

Answer

Significant increase in fuel rail pressure

Answer

A rich condition and black exhaust smoke

Answer

Increased fuel pump amperage draw only