Variable Induction Systems: Turbo
- Warm engine to normal operating temperature. Shut engine off. Using a 3-way connector, install vacuum gauge in vacuum line between Vacuum Switching Valve (VSV) and vacuum chamber for variable induction system. See Fig 1.NOTE: The VSV may also be referred to as the T-VIS VSV.
- Start engine. Vacuum gauge should indicate high vacuum at idle. Increase engine speed to greater than 4200 RPM. No vacuum should be indicated on vacuum gauge. If system does not operate correctly, proceed to step 3). If system operates correctly, all components are okay.
- Disconnect vacuum hose at vacuum chamber. Using vacuum pump, apply vacuum to vacuum chamber. Ensure vacuum chamber will hold vacuum. Replace vacuum chamber if defective and recheck system operation. If vacuum chamber is okay, proceed to step 4).
- Disconnect electrical connector from VSV. Using ohmmeter, check resistance between electrical terminals on VSV. Replace VSV if resistance is not 33-39 ohms. Check that no continuity exists between each electrical terminal and the body of the VSV.
- Apply air pressure to port "E" and ensure air passes out the filter. See Fig 2. Connect battery voltage to VSV terminals. Apply air pressure to port "E" and ensure air passes out port "F". See Fig 2. Replace VSV if defective and recheck system operation. If VSV is okay, check wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section.