Checking the vacuum system
WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect the vacuum hose from the pressure regulator and the intake pipe.
Check that the vacuum hose is undamaged and not clogged.
Replace the front pressure regulator if there is fuel in the vacuum hose.
Check the vacuum hose nipple on the intake pipe, clean if necessary.
Continue with "Connect the test equipment" (3).