Checking and adjusting the engine idle

Before adjusting and checking the idle speed of the engine, do the following:

• warm up the engine (oil temperature not less than 80°С);
• turn off consumers of electricity, including air conditioning, if installed;
• make sure that the idle and full load switches or the throttle position sensor are in good technical condition (ignition timing and engine speed should change when the switch or sensor connector is disconnected);
• make sure that the ignition timing and the gap between the electrodes of the spark plugs are set correctly;
• make sure that the solenoid valve is working: when the ignition is turned on, the valve should vibrate and hum.

The electric fan of the cooling system should not turn on during the test. Connect the control tachometer according to the operating instructions, connect the gas analyzer to tube A (pic. 2-100) carbon monoxide measurements (SO) in exhaust gases. Disconnect crankcase ventilation hose B (pic. 2-100 on the engine «RV») or 3 (pic. 2-103 on the engine «2E») and mute it. Start the engine at idle and let it run for about 1 minute. Disconnect connector blue 2 (pic. 2-101) coolant temperature sensor, then increase the engine speed three times to above 3000 rpm and leave the engine idling. Check the idle speed of the crankshaft and the CO content in the exhaust gases, which should be within 750-850 rpm and 0.5-1.5%, respectively. If the obtained values do not fit within the specified limits, remove the plugs from the idle speed adjusting screws and, alternately turning the idle air screw (to adjust the idle speed) and CO correction screw (pic. 2-102 and 2-103), to achieve the required values.










After adjustment, connect the crankcase ventilation hose and connect the fuel injection control subsystem coolant temperature sensor connector, put new plugs on the idle speed adjusting screws. Press the accelerator pedal several times and check the idle speed again, which should be within the required limits.

Disconnect the fuel pressure regulator vacuum hose from the throttle body fitting and close the opening of the fitting. In this case, the CO content should first increase briefly and then decrease. Then connect the hose.

Note. On the engine «2E» with an exhaust gas catalytic converter, the idling speed of the engine crankshaft and the CO content are automatically maintained within the specified limits by the controller commands.