Low Pressure Regulator (LPR)

The low pressure regulator (LPR) is a two stage regulator. The fuel enters the LPR at the intermediate stage pressure of 115 to 220 psi (793-1517 kPa). The first (primary) stage of LPR operation reduces the fuel pressure down to between 4-6 psi (28-41 kpa). The fuel pressure is then again reduced in the second (secondary) stage of the LPR down to between 2-5 inches (5.1-12.7 cm) of water column or around 0.21 psi (1.5 kpa). The fuel exits the LPR and flows through the low pressure hose and into the gas mass sensor/mixture control valve (GMS/MCV). The LPR contains two 1/8 in (3.175 mm) NPT test ports with plugs. The plugs are removable in order to allow the installation of a pressure gauge for diagnostic purposes. One port tests the first (primary) stage and the other port tests the second (secondary) stage. Refer to Fuel System Diagnosis for pressure checking procedures.