- carefully inspect the underhood space. Turn off the ignition, check the reliability of the fastening, the fit of all wires and connectors at the ignition module and high-voltage wires. Start the engine and listen to its operation - the crackling sound when the high voltage "to ground" is weak, but distinct. In complete darkness, the spark is clearly visible when the breakdown;
- -replace spark plugs regardless of their condition and mileage. Pay attention to the condition of the spark plugs: if it is abnormal, you may have to repair the engine or its systems.
A specific cause of jerks during steady movement of a car with an injection engine may be damage to the throttle position sensor. Additional symptoms confirming the malfunction of this sensor are the following:
- uneven engine operation at idle;
- reduction in maximum engine power.
The sensor is not disassemblable and therefore cannot be repaired. If a sensor malfunction is detected (see section "Engine management system"), it is replaced as a whole.
(The information can be read on the website vazbook.ru)