Checking 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 vapor is available then make sure it is used.
Wear protective gloves! Prolonged contact with fuel can cause skin irritation.
Keep a class BE fire extinguisher close by! Be mindful of the danger of sparks caused by short circuits and when connecting and disconnecting leads in electrical circuits.
Smoking is strictly forbidden.
Wear protective goggles.

Remove the valve cap. Connect pressure gauge equipment (part no. 83 93 852 ), and special tool (part no. 83 94 744 ) with pressure gauge, special tool (part no. 83 93 852 ) with "safety on" to the fuel-injection rail. Put "safety off" on the tool.

Fig 1: Illustration For Step 1
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Detach the vacuum hose from the pressure regulator and connect the pressure/vacuum pump (part no. 30 14 883 ), and pressure gauge (part no. 83 93 514 ).

Fig 2: Illustration For Step 2
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Activate the fuel pump with the diagnostic tool.

Fig 3: Identifying Fuel Pump And Diagnostic Tool
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Check the reading at atmospheric pressure. The reading should be 3 bar (43 psi).

Fig 4: Illustration For Step 4
Courtesy of SAAB-SCANIA OF AMERICA, INC.
SYSTEM PRESSURE REFERENCE

System pressure 3.0 (43) bar (psi)
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.

Fig 5: Illustration For Steps 5-6
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Pump up pressure in the pressure regulator with the vacuum pump. The system pressure should now rise by the same amount indicated on the pressure gauge. Disconnect the tool and reconnect the vacuum hose.