Tandem Control Valve System

The tandem control valve system is used to improve fuel atomization from main fuel injector. This is accomplished by regulating venturi vacuum to the tandem control valve diaphragm through an ECU controlled solenoid valve.

When engine RPM is low, solenoid is de-energized and spring-loaded control valve closes the tandem valve located above the injectors. This decreases the diameter of the throttle bore, increasing air velocity. This promotes improved atomization of injected fuel in response to the airflow rate. When engine RPM increases, solenoid is energized, venturi vacuum is allowed to act against the tandem control diaphragm to open tandem control valve.