TPS (3-Way) Solenoid Valve

This electro-vacuum valve has connections from intake manifold vacuum and to servo diaphragm. Solenoid portion is energized by electrical connections to engine speed switch (A/C relay on models so equipped) and ignition switch.

As engine speed switch senses engine RPM within operating range, it will open 3-way solenoid to allow passage of intake manifold vacuum, which positions servo diaphragm. This causes throttle plate to open slightly.