On automotive engines with multiple air inlet ports per cylinder the amount of air entering the cylinder through the secondary air inlet port is generally varied depending upon engine operating conditions. Thus, a control system must be utilized to open and close the secondary air inlet port to vary the amount of air passing therethrough. Current control systems utilize a vacuum actuator to open or close the secondary air inlet port thereby controlling the amount of air passing through the secondary air inlet port into the cylinder. However, under certain conditions the force achievable with a vacuum actuator is insufficient to satisfactorily open and close the secondary air inlet port in the intake manifold.
What is needed, therefore, is an actuator which is simple, compact, lightweight, reliable and yet provides sufficient torque and speed to satisfactorily open and close the secondary air inlet port. The present invention provides such an actuator.