Fuel injection system — idle speed and mixture adjustment

Note: On the Motronic system, only idle mixture adjustment is possible, since the idle speed is controlled by the idle speed controller.

1. Start the engine, warm it up to normal operating temperature, then shut it off and connect the tachometer according to the manufacturer's instructions.

2. Set the engine to idle and compare the idle speed to that given in the Specifications. If adjustment is needed, locate the adjusting screw on the throttle body (L3 system only) and rotate it as required (photo).



3. Stop the engine, connect the exhaust gas analyzer according to the manufacturer's instructions.

4. At idle at the specified speed, measure the value of CO and compare with that specified in the Specifications. If adjustment is necessary, turn the screw located on the side of the airflow sensor clockwise to richen the mixture or counterclockwise to lean it (photo).





5. Adjust idle speed if necessary.