Fuel Pressure Regulator: Testing and Inspection

Checking the fuel pressure regulator

WARNING: Removal of the fuel pressure regulator involves partial dismantling of the car's fuel system. The following points must therefore be observed in connection with this work:
- Work only in a well-ventilated area. If approved equipment for the extraction of fuel vapors is available, be sure to use it.
- Wear suitable gloves. Prolonged contact with fuel can cause skin irritation or dermatitis.
- Keep a class BE fire extinguisher near at hand. Be mindful of the danger of sparks caused by short circuits and when connecting and disconnecting leads in electrical circuits.
- No smoking anywhere in the vicinity,
- Wear protective goggles.





1 Remove the valve cap. Connect the pressure gauge (special tool, part No. 83 93 852) and adapter (special tool, part No. 83 94 744) with pressure gauge (special tool, part No. 83 93 852) to the fuel rail with the "safety" on. Use the tool with the "safety" off.





2 Remove tine vacuum hose from the pressure regulator and connect the pressure/vacuum pump (part No. 30 14 883) and pressure gauge (special tool, charge pressure meter, part No. 83 93 514).





3 Activate the fuel pump with the diagnostic tool.





4 Check the reading at barometric pressure. The reading should be 3 bar (43 psi).








5 Increase the negative pressure in the pressure regulator by means of the pressure/vacuum pump. System pressure should drop by the same amount as indicated on the pressure gauge.
6 Pump up the pressure in the pressure regulator with the vacuum pump. System pressure should now increase by the same amount as indicated on the pressure gauge.