2. Check that the basic ignition timing matches the nominal value, which for SOHC engines should be 5°±2°BTDC, for DOHC engines 5°±3°BTDC.
3. Stop the engine, turn off the ignition and connect the MUT-II to the diagnostic socket.
Attention! 4. Start the engine and let it run at 2500 rpm-1 within 2 min.
5. Install the gas analyzer probe (CO and CH) into the exhaust pipe.
6. Measure the concentrations of CO and CH at idling speed, which must correspond to the nominal values:
- CO concentration - no more than 0.5%;
- CH concentration - no more than 100 ppm.
7. If the measured values deviate from the nominal values, perform the following checks:
- fault code (diagnostic output);
- feedback control system (in case of normal operation of the feedback control system, the output signal of the oxygen sensor changes from 0 to 400 mV and from 600 to 1000 mV at idle);
- nozzles;
- ignition coil, high-voltage wires and spark plugs;
- no leakage in the exhaust gas recirculation system (EGR) and EGR valve;
- fuel vapor recovery system;
- compression.
Attention! If the concentration of CO and CH exceeds the nominal values, even in the case of normal test results for all the above points (elements), it is necessary to replace the three-way catalytic converter