Adjustment of idle speed, ignition timing and composition of the combustible mixture

1. Check for leaks in the vacuum hoses. normal contacts in electrical connectors, normal operation of the throttle and its position sensor. Check if the air cleaner is clogged.

2. Start the engine and warm it up. until the pointer of the temperature gauge reaches the middle of the scale. Engine speed should not exceed 1000 min^-1.

3. Open the hood and keep the rpm at 2000 rpm^-1 without load.

4. Two or three times raise the engine speed to 3000-4000 min^-1, then let the engine idle for 1 minute.

5. Turn off the ignition and disconnect the throttle position sensor connector. Start the engine again.

6. Two or three times raise the engine speed to 2000-3000 min^-1, then leave the engine idling.

7. Check up a corner of an advancing of ignition by means of a stroboscope. If necessary, adjust the angle by turning the distributor, after loosening the bolts of its fastening.



8. Check the base idle speed of the engine. If necessary, adjust by turning the adjusting screw.





9. Turn off the ignition and connect the throttle position sensor connector. Start the engine again.


10. Two or three times raise the engine speed to 2000-3000 min^-1, then check the idle speed. The RPM should be higher than the previous check. If the engine speed is not within the specified limits, check the IACV-AAC valve and its solenoid supply circuit. In rare cases, the control unit may be the cause, which can be verified by replacing it with a known good one.

11. Switch to diagnostic mode II. Maintain rpm 2000 min^-1 for 2 minutes without load, then, without reducing the speed, check the frequency of flashing of the malfunction indicator. It must be at least 0.5 Hz (more than 5 times in 10 s). If not, check the oxygen sensor circuit.





To check the sensor itself, disconnect the connector from the coolant temperature sensor and connect the connector pins with a 2.5 kΩ resistor (this corresponds to a coolant temperature of 20°C). Start the engine and warm it up until the pointer of the temperature gauge reaches the middle of the scale. Then two or three times raise the engine speed to 2000-3000 min^-1. Measure the CO content in the exhaust gases at idle. If it is more than 10%, the oxygen sensor must be replaced.

If replacing the sensor did not give the desired result, it is necessary to check the fuel pressure regulator, mass air flow sensor, injectors, coolant temperature sensor and control unit.