System Check (Protege DOHC)

Connect tachometer to IG terminal of diagnostic connector. See Fig 1 . Start engine, and operate it at idle. Ensure shutter valve actuator rod is retracted at idle. See Fig 2 . Gradually increase engine speed to 5000 RPM and ensure actuator rod extends. If necessary, check Variable Inertia Charging System (VICS) components.

Fig 1: Diagnostic Connector Terminal ID (MX-3 DOHC & Protege DOHC)

Courtesy of MAZDA MOTORS CORP.

Fig 2: Locating Shutter Valve Actuator & Rod (Protege DOHC)

Courtesy of MAZDA MOTORS CORP.