Scirocco L4-1781cc 1.8L DOHC (1986)
Differential Pressure Regulator: Description and Operation
Fig. 18 Fuel Distributor with Differential Pressure Regulator
The differential pressure regulator replaces the warm up regulator and the frequency valve found on CIS Lambda systems. The pressure regulator Fig.
18, is mounted on the fuel distributor. It acts as a pressure regulator which operates as a plate valve. The position of the plate can be varied causing a
differential pressure change between the lower chamber and the actuator, and therefore, a mixture change.
The signal controlling the pressure regulator comes from the ECU, based on the signals from the various sensors (temp, engine speed, etc.). With the
engine running, a constant system pressure of 5.2 - 5.6 bar (75 - 82 psi) is supplied at the fuel inlet. The pressure regulator is adjusted by variations of
current thereby determining the control pressure to the fuel distributor control plunger. The corresponding pressure change in the lower chamber causes
movement of the diaphragm, and influences the fuel volume flowing to the injectors.
