This solenoid valve controls fuel flow to the injection pump by opening or closing the fuel supply circuit when the ignition is switched on or off. It mounts directly on the injection pump housing and receives an electrical signal from the ignition switch; when energized, it allows fuel to pass to the pump’s internal metering components. A failed solenoid prevents the pump from receiving fuel, causing the engine to crank without starting. The valve from Granit is manufactured to match the original electrical resistance and plunger stroke, so the pump’s shut-off timing and fuel delivery remain consistent with the factory calibration. On installation, verify that the electrical connector seats fully and that the O-ring seal is intact to prevent air ingress into the fuel system.