Protection from unqualified intervention (filling)
To prevent unskilled intervention (or reducing its impact) on the screw for adjusting the minimum idle speed and the screw for adjusting the mixture composition (CO content in exhaust gases) Security seals or plugs may be installed.
Idle adjustments
Prerequisites
These conditions must be observed if it is necessary to check or adjust the idle speed or mixture composition (CO content in exhaust gases) in these modes. However, with any such adjustments, the following conditions must first be observed:
- the engine must be warmed up to normal operating temperature; and the cooling system fan should turn on twice;
- The automatic transmission gear selector must be in neutral.
Adjusting the minimum idle speed and mixture composition (CO content in exhaust gases) on this mode
Specifications:
minimum idle speed
- for models with manual transmission - 800±50 rpm;
- for models with automatic transmission (the gear selector is in position "N" or "R") − 1000±50 rpm;
- CO content in exhaust gases is no more than 0.2%.
1. Make sure that all auxiliary equipment (energy consumers) turned off.
2. Connect the tachometer, start the engine and let it idle for 2 minutes.
3. Increase the rotation speed to 3000-3500 rpm and let the engine run in this mode for one minute.
4. Return the engine to natural idle and check the rotation speed.
5. If necessary, adjust the speed by turning the screw "A" throttle stop behind the levers. In this case, the cooling system fan must be turned off.
Minimum speed adjustment screws (A) and mixture composition (IN)
6. Turn off the ignition.
7. Start the engine again and let it idle for 2 minutes.
8. Increase the rotation speed to 3000 −3500 min-1 and let the engine run at this mode for one minute.
9. Return the engine to natural idle. In this case, the cooling system fan must be turned off.
10. Check the CO content in the exhaust gases and compare its value with the technical specifications.
11. If adjustment is necessary, disconnect the vacuum tube "A" and seal the tube "IN" carburetor
12. Disconnect the multi-pin connector and vacuum tube from the air valve (exhaust manifold air bypass valve) electronically controlled (EACV) and close the valve "A".
Electronically Controlled Air Bypass Valve Connectors
13. Disconnect the oxygen sensor connector.
14. Turn off the ignition.
15. Start the engine again and let it idle for 2 minutes.
16. Increase the rotation speed to 3000 −3500 min-1 and let the engine run at this mode for one minute.
17. Return the engine to natural idle mode; in this case, the CO content in the exhaust gases should be within 2.5±0.5%.
18. If necessary (if the CO content is outside the specified limits) remove the safety plug and adjust the mixture adjustment screw "IN" (Fig.1).
19. Adjust the mixture composition by turning the adjusting screw clockwise to reduce the CO content in the exhaust gases (to lean the mixture) or counterclockwise to increase it (to enrich the mixture).
20. Connect the multi-pin connector and vacuum tube of the electronic air bypass valve (EACV).
21. Check the natural idle speed (minimum idle speed) and adjust it if necessary.
22. Turn off the ignition.
23. Turn off the fuse "Return"' ("BACK UP") for about 10 seconds to reboot ("reset to zero") control unit.
24. Install new safety plugs ("fillings") on the adjusting screws.
Adjusting the high idle speed
Specifications:
increased idle speed -3200±500 rpm.
1. Make sure the engine is cold.
2. Disconnect the vacuum tube from the unloading valve "A" control high idle speed and seal the tube "IN" using a plug.
3. Fully open and close the throttle valve to engage the high idle speed control cam.
High idle speed control cam
4. Start the engine and compare the value of the increased idle speed with the specifications,
5. If necessary, adjust the increased idle speed by turning the adjusting screw.
High idle speed adjustment screw
6. Connect the vacuum tube of the high idle speed control cam relief valve and warm up the engine to normal operating temperature.
7. After the engine warms up, the rotation speed should decrease to a value less than 1400 min-1, since the unloading valve removes the air damper thrust from the high idle speed control cam.
8. If the speed does not decrease to the specified level, disconnect the vacuum tube from the unloader valve "A".
9. Connect a vacuum gauge to the tube and make sure there is vacuum.
Connecting a vacuum gauge
10. If there is no vacuum, check the tube for damage or clogging.
11. If there is a vacuum, a malfunction of the unloading valve or jamming of the air damper rod can be assumed.