Intake manifold switchover - function - GF07.61-P-3028BK

ENGINE 113.967 in MODEL 219 

ENGINE 113.964 in MODEL 164.1 up to Model Year 8 

ENGINE 113.971 in MODEL 251 up to Model Year 8 

Fig 1: Intake Manifold Switchover Function Diagram

Courtesy of MERCEDES-BENZ USA

Task 

Pressurize intake manifold switchover aneroid capsule with vacuum or admitting air.

Function 

The variable intake manifold switchover valve is actuated by the ME-SFI control unit in line with the engine load and speed:

• When starting and at low rotational speeds, the variable flaps are opened - variable intake manifold switchover valve de-energized.
• At an engine load of more than 50% from approx. 1750 RPM up to approx. 3900 RPM the variable flaps are closed. The variable intake manifold switchover valve is opened by means of a ground signal by the ME-SFI control unit for this purpose. The intake manifold switchover diaphragm unit is pressurized with vacuum and operates the flap shafts.
• From, for example, 3900 RPM the variable intake manifold switchover valve is no longer actuated. The variable flaps open as a result of spring force.