Cabriolet, Golf GL/GTI, JETTA With AFC-DIGIFANT II

Install Fuel Pressure Gauge at service port on fuel plenum. Fuel pressure gauge must be able to read 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 the fuel pressure regulator. Fuel pressure should increase to approximately 44 psi (3.0 kg/cm² ). Turn engine off. After 10 minutes, residual pressure should be 29 psi (2.0 kg/cm² ). If system pressure is too high, the fuel pressure regulator should be replaced.
If residual pressure is too low, run the engine until system pressure is built up, pinch off Blue fuel return line. If pressure holds, replace the fuel regulator.