Air flow meter for the K-Jetronic system (BMW 5 Series E12)

The air flow meter is a Venturi tube 1 (see picture), inside which the pressure disk 2 moves, secured to the movable lever 8. The displacement of the pressure disk is transmitted through the lever to the distribution plunger of the fuel dispenser-distributor. The balance of the parallel movements of the pressure disk of the air flow meter and the distribution plunger is ensured by the counterweight 4.

Screw 3 is used to adjust the relative position of the air flow meter pressure disk and the fuel metering plunger, thereby changing the air-fuel ratio in the working mixture at all points of the acceleration curve. The position of screw 3 is adjusted at the factory. If necessary, screw 3 can be used to adjust the carbon monoxide (CO) content in the exhaust gases (when it is screwed down, the mixture becomes leaner).