Fuel Pressure Regulator: Notes
Each injection system (TBI & MPI) uses a different Fuel Pressure Regulator.
TBI regulator is an overflow type attached to the throttle body. TBI regulator is adjustable, and is not controlled by ECU. See SYSTEM/COMP TESTS article for specifications and testing procedures.
MPI regulator is vacuum balanced and non-adjustable. Regulator is mounted to output end of fuel rail and is connected to intake manifold vacuum. MPI regulator is not controlled by ECU. See SYSTEM/COMP TESTS article for specifications and testing procedures.