Digifant (Except Vanagon)
- Ensure ignition is off. Wrap a shop rag around service port on fuel plenum. Slowly loosen service port on fuel plenum to release fuel pressure. Install fuel pressure gauge at service port on fuel plenum. Fuel pressure gauge must have reading range of 0-50 psi. Start engine and allow it to idle. System fuel pressure should be approximately 36 psi (2.5 kg/cm2 ).
- Disconnect vacuum hose from top of fuel pressure regulator. Fuel pressure should increase to approximately 44 psi (3 kg/cm2 ). Turn engine off. After 10 minutes, residual pressure should be 29 psi (2 kg/cm2 ). If system pressure is too high, replace fuel pressure regulator.
- If residual pressure is too low, operate engine until system pressure builds up, then pinch off Blue fuel return line. If pressure holds, replace the fuel regulator. If fuel pressure is low, check the following for leaks.
- Fuel Lines
- Fuel Injectors
- Fuel Pump Check Valve