Caution: Do not attempt to adjust the damper lock screw. It is installed by the manufacturer.
1. Start the engine. Maintain rpm at 3000 without engine load (gearbox in neutral, automatic transmission selector in position [P] or [N]) until the electric fan turns on, then set the engine to idle.
2. Disconnect the vacuum hose of the fuel accumulator from the throttle body and attach the vacuum sensor.
3. Check for vacuum (by sensor) at idle.
If there is vacuum, check the throttle cable.
4. Check the vacuum value on the indicator with the throttle slightly open.
If the sensor does not indicate the presence of vacuum, check the pipe on the throttle body. If the pipe channel is clogged, clean it using carburetor cleaner.
5. Stop the engine and make sure that the throttle cable moves smoothly without snagging. Excessive wear or play on the damper shaft. The drive sector is stuck in the fully open position.
Gap between the locking screw and the drive sector in the fully closed position.
Replace the throttle body if there is excessive play in the throttle shaft or if the shaft binds when turning the throttle.