Control pressure regulator of the K-Jetronic system (BMW 5 Series E12)

The control pressure regulator ensures enrichment of the working mixture entering the combustion chambers during engine warm-up. On a cold engine, the bimetallic spring compresses the diaphragm valve spring, opening the fuel drain channel, which reduces the counteraction on the distribution plunger. A decrease in the control pressure with constant air flow causes an increase in the stroke of the pressure disk. As a result, the distribution plunger is additionally lifted, increasing the amount of fuel supplied to the injectors.

As the bimetallic spring heats up, the pressure on the spring diaphragm of the other control pressure regulator valve decreases and the drain channel slowly closes. The control pressure reaches the normal value and enrichment of the combustible mixture stops.

The control pressure regulator is installed on the cylinder block, due to which its temperature changes simultaneously with the engine temperature. This eliminates excessive enrichment of the working mixture at an average temperature.



(The original entry can be found on the portal: BMWMan.ru)