Idle adjustment

Idle speed control

■ The adjusting screw is located in the throttle body port.

■ Loosen the lock nut and set the speed of the warmed engine to 850 rpm. Secure the screw with the nut.

Setting the basic throttle position

■ Set the throttle adjusting screw so that it is, that a 0.05 thickness feeler could be inserted into the gap between the damper and the wall…0.1 Mm, where the smaller value is recommended.

Regulation of CO concentration

■ Bring the engine to normal operating temperature (minimum oil temperature 80ºC).

■ Connect a qualified flue gas analyzer. Insert the probe into the exhaust pipe to a depth of at least 30 cm.

■ Remove the seal from the air flow meter and turn the adjustment screw, so that the concentration of CO in the exhaust gas is 1.0 ± 0.5%. When turning the screw clockwise, the CO content increases, while to the left - it decreases.

■ If the engine is equipped with a pulse system to reduce the toxicity of exhaust gases, the system should be closed before regulation.

■ If, during inspection, a significant deviation from the required value is found, check the connections between the flow meter and the motor.

■ If the CO content is too high, the injectors for leaks must be checked. To do this, remove after, stopping the engine, injectors (the fuel supply remains connected). Turn on the fuel pump as in the discharge pressure measurement and check, that the injectors do not leak drops of fuel delivered under pressure. Damaged injectors must be replaced.

■ Adjustments and wider repairs are not recommended. In doubtful cases, contact Bosch Service.