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Differential Pressure Regulator (DPR)

The DPR is mounted on side of fuel distributor. An electrically operated plate valve combined with fixed outlet orifice, governs pressure in lower chamber. See Fig 1 . Pressure change in lower chamber causes movement of diaphragm and fine tunes fuel volume flow to injectors. Actuating signal comes from ECU and can range from -60 to +120 mA, depending upon engine operating conditions.

Fig 1: Differential Pressure Regulator
G121490Courtesy of VOLKSWAGEN UNITED STATES, INC.