Idle speed and mixture adjustment (Pierburg)

Adjustment screws

To adjust the idle speed and the quality of the mixture, it is necessary to have a tachometer and an exhaust gas analyzer.

1. Check the condition of the air filter and replace if necessary.

2. Warm up the engine to operating temperature.

3. Turn off all electrical consumers.

4. Disconnect the radiator fan temperature sensor connector and close both contacts with a jumper to turn the fan on permanently.

5. Check ignition start setting.

6. Connect a tachometer to the engine (with the ignition off) and gas analyzer.

7. Increase the engine speed to 3000 rpm and hold it for 30 seconds, and then turn the engine to idle.

8. Take instrument readings.

9. If the idle speed deviates from the norm, set the required speed with the mixture amount adjusting screw.

10. If the CO content deviates, remove the protective cap from the mixture quality screw, increase the engine speed to 3000 rpm and hold it for 30 seconds, and then switch the engine to idle and, turning the mixture quality screw, set the required CO level.


11. When changing the idle speed, adjust them with the mixture adjustment screw.

Attention! It is possible to take instrument readings and make adjustments only after stabilization of the readings of measuring instruments.

12. In the absence of a gas analyzer, approximate adjustment of the quality of the mixture can be made as follows. With the engine running, turn the mixture quality screw inward until the idle speed begins to noticeably decrease, then unscrew the screw slightly in the opposite direction until the engine runs smoothly.