Vehicle fuel system with active accumulator

A fuel delivery system for a vehicle having an internal combustion engine, the fuel delivery system comprising:

• a fuel injection system including a fuel rail and fuel injectors configured to supply fuel to the engine;
• a fuel supply line configured to supply fuel from a fuel tank to the fuel injection system;
• a fuel pressure sensor configured to sense a pressure in the fuel delivery system;
• an active expansion chamber (AEC) accumulator fluidly coupled to the fuel supply line and comprising:
• a housing defining an interior chamber and an adjustable expansion chamber;
• a plunger assembly separating the interior chamber and the adjustable expansion chamber;
• and
• an actuator configured to selectively move the plunger assembly to actively adjust a volume of the adjustable expansion chamber;
• and
• a controller in signal communication with the AEC accumulator and the fuel pressure sensor, the controller configured to detect a pressure change condition in the fuel delivery system and, in response to the detected pressure change condition, automatically adjust the volume of the adjustable expansion chamber to maintain the pressure of the fuel delivery system below a predetermined threshold to thereby facilitate preventing fuel leakage at the fuel injectors when the engine is shut off,
• wherein the controller only adjusts the volume of the adjustable expansion chamber when the vehicle engine is off.