Mixture Control Valve

This normally closed valve prevents afterburning on deceleration. The valve acts by adding secondary (air pump) air to intake manifold during deceleration. When high intake manifold vacuum is sensed, valve opens and air pump air is directed to intake manifold to combine with rich mixture caused by rapid closing of throttle blades.

Fig 1: Isuzu & LUV Mixture Control Valve

Courtesy of ISUZU MOTOR CO.

Fig 2: Isuzu & LUV Air Injection System California Models

Courtesy of ISUZU MOTOR CO.

California models use a Vacuum Switching Valve.