Throttle Opener

Throttle Opener System, 1976

California vehicles equipped with manual transmission are equipped with this system to protect the catalytic converter from abnormally high temperatures by maintaining an optimum air-fuel mixture to the engine during deceleration. This system incorporated a servo diaphragm and throttle lever which opens the primary throttle valve in the carburetor. A vacuum control valve issued to detect intake manifold vacuum and actuates the servo diaphragm during deceleration.

Throttle Opener System, 1977-82

This system opens the primary throttle valve slightly so that an optimum amount of air-fuel mixture is fed to the engine to reduce emissions during deceleration, since during deceleration, the air-fuel mixture entering the engine is not sufficient for complete combustion.

This system consists of a servo diaphragm connected to a throttle lever, a three way solenoid valve which controls intake manifold vacuum to the servo diaphragm and an engine speed switch which grounds the throttle positioner circuit.

When engine speed is above 1700 RPM, the engine speed switch opens the throttle positioner circuit and the three way solenoid valve allows intake manifold vacuum to actuate the servo diaphragm and increase engine speed.

When engine speed is less than 1700 RPM, the engine speed switch grounds the throttle positioner circuit. The three way solenoid valve prevents vacuum from applying the servo diaphragm.

On 1979-82 models with air conditioning, when the air conditioning is turned on, the air conditioning relay opens the throttle positioner circuit regardless of the position of the engine speed switch. With the three way solenoid valve energized, vacuum is applied to the servo diaphragm to increase engine speed.