System Pressure (Quantum & Quantum Synchro)
- Using new sealing washers and line adapter (VW 1318/5 ), connect pressure gauge (VW 1318 ) between fuel cold start valve and lower chamber connection of fuel distributor. Gauge lever positions: A-open, B-closed. See Fig 1.
- Switch OFF (US 4480/3 ) remote control. Remove fuel pump relay and jump socket with (US 4480/3 ) remote control. Remove harness connector from differential pressure regulator. Open valve on pressure gauge (VW 1318 ). Turn ON remote control (US 4480/3 ). System pressure reading should be 75-82 psi (5.2-5.7 kg/cm2 ).
- If pressure reading is low, check fuel pump delivery quantity. If okay, replace fuel pressure regulator.
- If pressure is above specifications, disconnect fuel tank return line from fuel pressure regulator and repeat test. System pressure must be 75-82 psi (5.2-5.7 kg/cm2 ). If pressure is okay, check for plugged fuel return line. If pressure is not within specifications, replace fuel pressure regulator.
NOTE:
System pressure is NOT adjustable on Quantum/Quantum Synchro models.