An injection molding system comprised of: an injection machine having a barrel and a screw for injecting an injection fluid to one or more downstream gates of one or more cavities of one or more molds during a first injection cycle, during a second injection cycle following the first injection cycle, and during other subsequent injection cycles following the second injection cycle, a distribution manifold for receiving the molten injection fluid from the barrel and distributing the injection fluid through one or more fluid delivery channels in the manifold that deliver the injection fluid to one or more downstream fluid passages that mate with corresponding ones of the one or downstream gates to the one or more mold cavities, a valve (11, 11a, 11b, 11c) associated with each downstream gate, each valve (11, 11a, 11b, 11c) comprising an actuator interconnected to and reciprocally driving a corresponding valve pin at one or more selectable upstream travel velocities that include a maximum upstream travel velocity, the valve pins being driven between a gate closed position and a selected maximum upstream gate open position defining a complete upstream path of travel for each injection cycle, a sensor adapted to sense pressure of the injection fluid in the barrel or in an inlet that delivers injection fluid from the barrel (19, 19a) to the manifold, a controller to which the sensor sends a signal indicative of the sensed pressure, the controller receiving the signal and including instructions that use only the signal as a control value that controls one or more valve pins to be driven, during the second injection cycle, through at least a portion of the complete upstream path of travel at one or more reduced upstream travel velocities during the second injection cycle that are less than the maximum upstream travel velocity, the instructions further using the control value as a variable in an algorithm that establishes an instruction value for the one or more reduced upstream velocities that operates to drive the one or more valve pins to effect a rate of flow of injection fluid through each gate corresponding to the one or more valve pins during the second injection cycle, and during other subsequent injection cycles following the second injection cycle, that is either reduced or is substantially constant relative to the rate of flow of injection fluid during the first injection cycle over at least a portion of the complete upstream path of travel of the one or more valve pins. an injection machine having a barrel and a screw for injecting an injection fluid to one or more downstream gates of one or more cavities of one or more molds during a first injection cycle, during a second injection cycle following the first injection cycle, and during other subsequent injection cycles following the second injection cycle, a distribution manifold for receiving the molten injection fluid from the barrel and distributing the injection fluid through one or more fluid delivery channels in the manifold that deliver the injection fluid to one or more downstream fluid passages that mate with corresponding ones of the one or downstream gates to the one or more mold cavities, a valve (11, 11a, 11b, 11c) associated with each downstream gate, each valve (11, 11a, 11b, 11c) comprising an actuator interconnected to and reciprocally driving a corresponding valve pin at one or more selectable upstream travel velocities that include a maximum upstream travel velocity, the valve pins being driven between a gate closed position and a selected maximum upstream gate open position defining a complete upstream path of travel for each injection cycle, a sensor adapted to sense pressure of the injection fluid in the barrel or in an inlet that delivers injection fluid from the barrel (19, 19a) to the manifold, a controller to which the sensor sends a signal indicative of the sensed pressure, the controller receiving the signal and including instructions that use only the signal as a control value that controls one or more valve pins to be driven, during the second injection cycle, through at least a portion of the complete upstream path of travel at one or more reduced upstream travel velocities during the second injection cycle that are less than the maximum upstream travel velocity, the instructions further using the control value as a variable in an algorithm that establishes an instruction value for the one or more reduced upstream velocities that operates to drive the one or more valve pins to effect a rate of flow of injection fluid through each gate corresponding to the one or more valve pins during the second injection cycle, and during other subsequent injection cycles following the second injection cycle, that is either reduced or is substantially constant relative to the rate of flow of injection fluid during the first injection cycle over at least a portion of the complete upstream path of travel of the one or more valve pins.