Throttle Valve

CIS-E Throttle Valve:

The Throttle Valve is mounted on the intake manifold inlet downstream of the mixture control unit. The Throttle Valve is of the two barrel side draft type with progressive throttle linkage. The function of the Throttle Valve is to regulate air flow into the engine, the more it is open the greater the air flow into the engine. Throttle Valve operation is controlled by the throttle cable and the accelerator pedal. The Throttle Valve does not control idle speed, this is done by a separate idle stabilizer valve. You adjust idle speed on CIS-E Motronic systems not by fine adjustment of the Throttle Valve, but by controlling a small amount of air that is allowed to bypass the throttle. This is more reliable since it's independent of throttle cable stretch or wear in the throttle valve mechanism.

Components attached to the Throttle Valve provide input signals to the Motronic control unit. On manual transmission cars, a throttle valve switch signals whether the Throttle Valve is closed (idle position) or open.

Automatic transmission cars are fitted with a throttle valve potentiometer. It signals closed throttle (idle position) and full-throttle for the Motronic control unit, as well as throttle position for the automatic transmission control unit.