Attention! The rated idle speed is set at the factory with the idle speed screw (SAS) and usually does not require additional adjustment during operation.
Attention! If by mistake the factory setting was violated, then a significant increase in the idling speed may occur or its decrease when an additional load on the engine is turned on (e.g. air conditioner compressor). If this happens, then the adjustment is carried out as described below.
Attention! Before adjusting, make sure that the spark plugs, injectors, idle speed control (ISC) are serviceable, and the compression in the cylinders is in the range from the nominal to the maximum allowable value, and that the difference in compression between the cylinders does not exceed the maximum allowable value.
1. Prepare the vehicle for testing: Warm up the engine to normal coolant operating temperature.
2. Connect the MUT-II to the 16-pin diagnostic socket.
Attention! When connecting the MUT-II, connect with «weight» diagnostic output.
3. Remove the waterproof plug from the base ignition timing connector.
4. With wire clamp type «crocodile» connect with «weight» the output of the connector for adjusting the basic ignition timing.
5. Start the engine and let it idle.
6. Check up frequency of rotation of a cranked shaft in an idling mode.
Rated value:
- for 4G92 engine - (750±50) min-1;
- for 4G93 engine - (800±50) min-1.
Attention! On a new car (with a mileage of not more than 500 km) idling speed can be less than the nominal by 20-100 minutes-1. Adjustment in this case is not required.
If the engine stalls or the idle speed is too low on a car with a mileage of more than 500 km, then foreign particles have probably been deposited on the throttle body, so it needs to be cleaned.
Pic. 7.7. Base idle speed adjustment
7. If the idle speed differs from the nominal, then adjust it by turning the idle speed adjustment screw (SAS) (pic. 7.7).
Attention! If the idle speed is higher than the rated speed even when the idle speed screw is fully turned (SAS), check if the paint on the throttle lever stop screw is damaged (Fixed SAS), i.e. Has it been previously adjusted? If the paint is damaged, adjust the position of the throttle lever stop screw (Fixed SAS).
8. Turn the ignition key to position «OFF» («OFF»)
9. Disconnect the wire with the clip «crocodile» from the base ignition timing controller output and reset the connector.
10. Start the engine and let it idle for 10 minutes. Make sure the engine is idling normally.