Fuel Volume Control Valve
WARNING: This page is about a different car, the 2020 Ford F-550 Super Duty, 2020 Ford F-450 Super Duty, 2020 Ford F-350 Super Duty, 2020 Ford F-250 Super Duty, and 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
The PCM regulates fuel volume by controlling the duty cycle of the fuel volume control valve. For the Transit, the fuel volume control valve is a normally closed valve. For all others, the fuel volume control valve is a normally open valve. A high duty cycle indicates low fuel volume is being admitted to the high pressure fuel injection pump or low pressure. A low duty cycle indicates high volume is being admitted to the high pressure fuel injection pump or high pressure. The fuel volume control valve is mounted on the high pressure fuel injection pump.