4000S Quattro (Canada) L5-2144cc 2.14L SOHC (JT) (1986)
Fuel Pressure Regulator: Description and Operation
Fig. 13 Fuel Pressure Regulator
Because of the electronic controls in this injection system, the control pressure (warm up) regulator and pressure relief valve (used in the CIS-Lambda
system) are no longer needed. Taking their place is a diaphragm type pressure regulator, Fig. 13, that maintains system pressure at approximately 5.4
bar (78 psi), and control pressure at 0.2 bar (3 psi) below system pressure. The pressure regulator also acts as a one way check valve to maintain
pressure in the system once the engine has been shut off.