190E 2.3 (201.024) L4-2.3L (102.961) (1984)
Fuel Pressure Regulator: Description and Operation
Fig. 13 Fuel Pressure Regulator
The primary pressure regulator is a variable resistance in the fuel return line from the fuel distributor. The function of the regulator is to maintain a
control pressure that is a constant 0.4 bar (5 psi) below the system pressure.