An apparatus for controlling the rate of flow of fluid mold material from an injection molding machine to a mold cavity, the apparatus comprising: a manifold having a fluid delivery channel, an actuator interconnected to a valve pin having a tip end drivable between a first position, a second position upstream and a third position upstream of the second position, the actuator and the valve pin being translationally driven by a valve system adjustable between a start position, a plurality of intermediate drive rate positions and a high drive rate position, a pressure sensor and a controller, the pressure sensor sensing a metered pressure of a drive fluid, the controller instructing the valve system to drive valve pin continuously upstream and including instructions that instruct the valve system to move according to a predetermined profile of metered pressures from the start position to selected intermediate drive rate positions and subsequently to the high drive rate position.