CO% Adjustment Using CO Meter

CO-Adjustment Using CO Meter





- Connect tachometer.
- Connect stroboscope.
- Connect CO% meter.

Check/Adjust Idle Speed
- Warm-up engine
- Run engine at 1500 rpm.

NOTE: Warm-up engine until radiator thermostat opens and then for a further 10 minutes.





- Ground blue-white wire to close idle air control valve.

NOTE: Switch off AC as applicable.

- Check idle speed.





- Adjust engine speed with idle adjustment screw to 700 rpm.
- Disconnect ground from test point.
Engine speed should increase to 750±20 rpm

If values are incorrect: check/adjust Throttle Body and/or Throttle Cable/Linkage.

Check/Adjust Ignition Setting
Idle speed fluctuations can affect ignition setting. Make sure that fluctuations are not greater than 25 rpm.
If greater, check air control valve hoses for blockages.
- Check ignition timing with stroboscope.
Ignition setting should be 12° BTDC at idle.





- Adjust setting by turning distributor body.

Check CO





- Disconnect Lambda sond
- Check CO-content.
CO-content = 0.4-0.8 %.

Adjusting CO
CO should only be adjusted after all possible faults have been checked/rectified.

- Turn off engine.





- Drill two 2 mm (0.08 in.) holes in plug.
- Withdraw plug with circlip pliers.
- Start engine.
- Adjust CO content.





Counterclockwise reduces CO
Clockwise increases CO
Adjustment range = 15 turns.





- Seal CO adjustment screw
Always use a new plug.
- Push plug into position.
- Disconnect test instruments.