System Operation
- Warm engine to normal operating temperature. Shut engine off. Using 3-way connector, install vacuum gauge in vacuum line between variable induction Vacuum Switching Valve (VSV) and variable induction vacuum actuator. Variable induction VSV is located below intake manifold, near cylinder block. See Fig 1.NOTE: Variable induction VSV may also be referred to as the T-VIS VSV.
- Start engine. Vacuum gauge should indicate high vacuum at idle. Note that variable induction vacuum actuator rod moves inward so valves on variable induction system close.
- Increase engine speed to greater than 4200 RPM. No vacuum should be indicated on vacuum gauge. Variable induction vacuum actuator rod should move outward so valves are open. If system operates correctly, all components are okay. If vacuum reading was obtained at idle, but variable induction vacuum actuator does not operate, check variable induction vacuum actuator.
- If no vacuum reading was obtained at idle, check vacuum supply to vacuum tank. Vacuum tank is located below the intake manifold. See Fig 1.
- If no vacuum supply exists, check vacuum hoses and circuit. If vacuum supply is okay, check vacuum tank, variable induction VSV and all hoses. If components are okay, check wiring circuit for variable induction VSV. See wiring diagram in the WIRING DIAGRAMS article.
- The Engine Control Module (ECM) controls variable induction VSV ground circuit on Green/Black wire. ECM is located at driver's side rear corner of engine bay. Power is supplied to variable induction VSV through EFI main relay.
- If necessary to check EFI main relay, see EFI MAIN RELAY under RELAYS. Repair as necessary and recheck system operation.