Air Regulating Valve
- Screw in throttle by-pass screw completely when engine is running at steady idle speed. After brief deviation the idle speed must return to 800 RPM.
- Pull off electrical connector on air regulating valve. Connect center connection of valve with 12-volt supply. Connect an outer connection with ground. Valve must turn against stop. Exchange outer connections. Valve must turn to other stop.
- Connect a new air regulating valve on the wire plug to check activation of the valve from the control unit. The air regulating valve must vibrate noticeably (frequency activation) with engine running.
- If engine speed is boosted with the by-pass screw, the air regulating valve must move in closing direction. The air regulating valve must turn in opening direction when speed drops.