System Check
Connect tachometer to engine. Start engine, and operate at idle. Manually open throttle valve. Ensure shutter valves No. 1 and 2 operate as specified. See VRIS RPM SPECIFICATIONS table. See Fig 1 . If necessary, check Variable Resonance Induction System (VRIS) components.
VRIS RPM SPECIFICATIONS (MX-6 & 626)
| RPM | Position | |
|---|---|---|
| Shutter Valve No. 1 | ||
| Less Than 3250 | Closed | |
| 3250-4250 | Open | |
| 4250-6250 | Open | |
| Greater Than 6250 | Closed | |
| Shutter Valve No. 2 | ||
| Less Than 3250 | Closed | |
| 3250-4250 | Closed | |
| 4250-6250 | Open | |
| Greater Than 6250 | Closed | |