Pumps and injectors having a control valve spring arrangement configured to provide a force step when the control valve is at a rate shape position, and related methods for operating a control valve, are provided. The control valve is moveable over a stroke range between an open position and a closed position. The stroke range includes a rate shape position. The control valve spring arrangement is configured to provide a first spring force when the control valve is between the closed position and the rate shape position, and to provide a second spring force that is less than the first spring force when the control valve is between the rate shape position and the open position.