A system for injecting an injection fluid into a pipeline includes an injection pump, a timer for initiating sequencing of the pump, a control valve for controlling the flow of pressurized fluid to power the injection pump, a controller for controlling operation of the control valve, and an electric motor responsive to the controller for rotating a cam on the motor shaft to open and close the control valve. The injected fluid may be methanol, so that the system automatically injects methanol into a pipeline which transmits natural gas. In one embodiment, the system includes a temperature sensor and a flow sensor for inputting signals to the controller.