Retard Cylinder (900 Turbo)
WARNING: This page is about a different car, the 1992 Saab 9000 and 1992 Saab 900. However, it is still accessible from the selected car via links, so may be relevant.
If timing does not retard as boost pressure increases, check hose from throttle body to distributor. If hose is okay, repair or replace distributor.