Checking the fuel pressure regulator

WARNING: The check involves partial dismantling of the car's fuel system. The following points should therefore be observed in connection with the 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 suitable 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.

Reduce the fuel pressure by removing the fuel pump fuse no. 32 while the engine is idling. Turn off the ignition once the engine has stopped.

Fig 1: Illustration For Step 1
Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fit the fuel pump fuse, no. 32.
Remove the engine cover.
Unscrew the valve cap from the fuel rail service nipple. Connect the pressure gauge equipment, part no. 83 93 852, and adapter, part no. 83 94 744. Connect the adapter with the "safety on" to the fuel rail.

Fig 2: Illustration For Step 3
Courtesy of SAAB-SCANIA OF AMERICA, INC.

"Safety-off" the adapter.
Detach the vacuum hose from the fuel pressure regulator and connect pressure/vacuum pump, part no. 30 14 883, and charge pressure gauge, part no. 83 93 514.

Fig 3: Illustration For Step 4
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Start the fuel pump with the diagnostic tool.

Fig 4: Illustration For Steps 5-7
Courtesy of SAAB-SCANIA OF AMERICA, INC.

It may be necessary to restart the pump during the check, as it is active for only 30 sec. each time it is started with the diagnostic tool.
Take a reading at atmospheric pressure. The value should be 3 bar (43 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.
System pressure: 3.0 bar (43 psi)
Pump up pressure in the fuel pressure regulator with the vacuum pump. System pressure should now rise with the same amount as indicated on the pressure gauge.

Fig 5: Illustration For Step 8
Courtesy of SAAB-SCANIA OF AMERICA, INC.

Make sure the pump is not activated.
"Safety-on" the adapter and remove the pressure gauge equipment from the fuel rail service nipple. Screw on the valve cap.
Remove the pressure/vacuum pump from the fuel regulator and connect the vacuum hose.
Fit the engine cover.