1. Engine malfunction - decreased compression in one or more cylinders, additional air being sucked into the engine intake tract. Coking of the exhaust system or damage to the exhaust gas neutralizer.
2. Malfunction of the fuel system - clogged injectors and fuel filter, fuel supply system hoses. Insufficient fuel pump supply. Use of low-quality fuel.
3. Malfunction of the ignition system - failure of the spark plug, breakdown of the high-voltage circuit of the system.
4. Malfunction engine management systems — failure of the system sensors. If any sensor fails, the electronic control unit switches to a backup program, allowing you to get to a garage or car service, but the engine's power and economic characteristics are reduced.
5. Clutch slippage due to wear or failure adjustments.
6. Malfunction of the braking system - braking of one or more wheels while driving, incorrect adjustment of the parking brake.
7. Insufficient air pressure in the tires.
8. Overloading the vehicle.
A full diagnostic of the car should be carried out by highly qualified specialists using special diagnostic equipment, so contact a car service.
You can carry out the following work yourself.
1. Check and adjust the air pressure in your tires to the correct level.
2. Check the operation of the service brake system and the parking brake. Remove the wheels not necessary for this. Find a flat section of the road and in dry, windless weather, conduct a run to determine the coasting of the car. The car should be fully fueled, with only the driver in the car. Accelerate the car to 50 km/h, level off, then turn off the gear and coast to a complete stop. Do another run in the opposite direction. The coasting should be about 500 m.
3. Check the operation of the ignition system as described above.
4. Check the operation of the clutch.
The initial check is carried out on a level area free of obstacles.
[The article is copied from the website vazbook.ru]
Set the choke control knob to a high idle speed of approximately 1500 min⁻¹.
Press the clutch, engage first gear and press the brake pedal. Then begin to smoothly release the clutch pedal.
If the engine stalls, the clutch is in good condition and does not slip. In this case, check the clutch drive adjustment.