The Ecotronic carburetor is a register carburetor with which the mixing proportion is changeable in almost every operational area and
works together with the Lambda control.
The choke flap (here called the pre-throttle) works in the Ecotronic carburetor, not only during the cold start, but in all operational areas, and is operated by a servo-motor (incl. control device). Through brief closing of
the pre-throttle, the mixture is enriched, through opening, it becomes leaner, exactly according to the signal from the Lambda sensor. So that this also functions during idling, the pre-throttle also controls the idling-
needle valve through a linkage system.
Because of this regulation, some functions of the register carburetor are unnecessary, e.g., the acceleration mechanism. When accelerating, the pre-throttle is closed for a short period. The idling is regulated by a
throttle-flap actuator and a control device as well. This uses the force of the negative atmospheric pressure to slightly open the throttle valve, or to close it. The controlling is done by two electro-magnetic valves.
Why has the Ecotronic carburetor not been able to assert itself? On the one hand, it cannot compete against the multi-point
injection, and on the other hand, it is still more complex than a central injection. 05/10