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Fuel Pressure: Digifant

WARNING: This page is about a different car, the 1993 Volkswagen Passat, 1993 Volkswagen Fox, 1993 Volkswagen EuroVan, 1993 Volkswagen Corrado, and 1993 Volkswagen Cabriolet. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ensure ignition is off. Wrap a cloth 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 ).
  2. 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.
  3. 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 for leaks at fuel lines, fuel injectors and fuel pump check valve