Wastegate Solenoid
WARNING: This page does not describe the selected car, but rather 35 other vehicles, including the 1992 Pontiac Trans Sport, 1992 Oldsmobile Silhouette, 1992 Oldsmobile Bravada, 1992 GMC Yukon, and 1992 GMC Vandura Special. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect electrical connector from solenoid. Apply battery voltage and ground to solenoid electrical terminals. With solenoid energized, apply vacuum to one solenoid vacuum fitting with a hand-held vacuum pump. Vacuum should hold only while solenoid is energized.