Which component uses a spring to change the amount of pressure in the system?

• A. Float Bowl
• B. Fuel Pressure Regulator
• C. Venturi
• D. Throttle Plate

Answer: (B)

Fuel pressure regulators use a spring to set and maintain the pressure in the fuel system. The spring provides a baseline force on a diaphragm; fuel pressure pushes against that diaphragm to close a valve. When pressure would rise above the spring’s setting, the diaphragm yields and opens the valve to bleed off excess fuel, keeping pressure steady. The regulator also responds to engine vacuum on the other side of the diaphragm, so it can adjust pressure with changing operating conditions rather than holding it fixed. This combination ensures a constant, appropriate fuel pressure for the engine.

The other components don’t regulate system pressure in this way: the float bowl mainly maintains fuel level, the venturi creates a suction effect to help draw fuel but doesn’t control pressure, and the throttle plate controls air flow rather than fuel pressure.