- Before adjusting the idle speed, warm up the engine to operating temperature.
- Turn off all electrical consumers. The fan should not turn on either. The air filter must be installed.
- Start the engine and take readings of the idle speed. If it is more than 700 rpm, check whether the adjusting lever touches the adjusting screw when the gas pedal is fully depressed. Otherwise, adjust the idle speed.
- Loosen the locknut of the idle speed adjustment screw at the location shown in Figure 322 (with a regular key), and use a second key to turn the adjusting bolt until the specified idle speed is obtained. Retighten the locknut.
Pic. 322. Location of the idle speed adjustment bolt. Use two wrenches to loosen or tighten the locknut
Increase the speed and make sure that after releasing the gas pedal the engine returns to idle speed. If this does not happen, the throttle length must be adjusted. When the gas pedal is released, the lever of the high-pressure fuel pump should rest against the end of the adjusting bolt.