Manual Transmisssion

Throttle Controller Operation:

Dashpot System

Description

The throttle controller functions as a dashpot and a cranking opener.

The dashpot prevents the throttle valve from shutting rapidly, which helps control hydrocarbon emissions during vehicle deceleration or when gear shifting. The throttle valve closes when vacuum in the throttle controller diaphragm overcomes the diaphragm spring. This vacuum increases gradually because of the orifice in the vacuum line.

Thus, the diaphragm slowly pulls the diaphragm rod against the force of the spring, and the throttle valve is closed gradually.

During cranking, low manifold vacuum allows the throttle controller to push the throttle lever and provides the proper throttle valve angle to assist engine starting.