What is the reason why the 20 13 viano hot car is shivering?

1. air intake system failure

(1) There is too much dust on the throttle and air intake or the air filter is blocked.

Too much dirt on the throttle and air intake or the air filter element is blocked, the cross-sectional area of the idle channel becomes smaller, the air quantity entering the cylinder is less than normal, the mixed gas becomes thicker, and the cylinder is not fully burned, resulting in engine jitter.

(2) Leakage of intake pipe or EGR valve

The intake pipe or EGR valve leaks, the amount of air entering the cylinder is greater than the normal value, the mixture becomes thinner, and the dynamic performance of the cylinder decreases. If the EGR valve is not tightly closed, part of the exhaust gas will enter the cylinder, resulting in high residual exhaust gas, deterioration of the combustion situation, and engine power decline, leading to engine jitter.

(3) air flow meter or intake pressure sensor failure

If the air flow meter or intake pressure sensor fails, the intake air volume measurement is inaccurate, and the fuel injection amount of the fuel injection system is inaccurate, resulting in abnormal air volume entering the cylinder and uncertain mixture concentration, resulting in engine jitter.

(4) Idle speed control system failure

Idle speed control system mainly controls the air intake at idle speed, and increases or decreases the fuel injection quantity according to the air intake to achieve the appropriate air-fuel ratio. If the idle control system (such as throttle position sensor, idle valve, etc.). ) failure, the engine will not be able to achieve accurate air-fuel ratio control, engine power performance decline, leading to engine jitter.

2. Fuel system failure

(1) Oil supply pressure failure

There are many reasons for the failure of oil supply pressure: the fuel filter is blocked; The fuel pump is damaged or the filter screen is blocked; The pump pressure of the fuel pump is insufficient; The spring force of the fuel pump safety valve becomes smaller; The fuel pressure regulator is damaged and so on. Abnormal fuel supply pressure causes the mixture to be too rich or too lean, which reduces the engine power performance and makes the engine shake.

(2) Fuel injector failure

Common faults of injector include: damaged injector coil; The fuel injector is stuck; The syringe is blocked; Poor seal of fuel injector, etc. The failure of injector will lead to uneven fuel injection and poor atomization in each cylinder, resulting in uneven output power of each cylinder and engine jitter.

3. Ignition system failure

(1) spark plug

Spark plugs can introduce high-voltage electricity into the combustion chamber of an engine, generate electric sparks between electrodes, and ignite combustible mixture. If the spark plug electrode gap is incorrect, carbon deposition or ablation occurs on the spark plug electrode, the spark plug insulator cracks, the spark plug does not flash or the spark energy is weak, resulting in poor combustion of the mixed gas, unbalanced engine power and engine jitter.

(2) Ignition module or ignition coil

Failure of ignition module or ignition coil can also lead to misfire or weak spark energy, resulting in engine jitter. At present, the ignition module and ignition coil of most vehicles are integrated.

(3) Ignition control circuit and ignition timing

In the computer-controlled ignition system, ECU receives signals from various sensors and other devices related to engine working conditions, calculates, analyzes and judges them, and then sends instructions to the executive device to realize ignition control. Sensor or ignition control circuit is faulty, and ECU gives wrong instructions, resulting in incorrect ignition advance angle. Common causes are: air flow meter or intake pressure signal failure; Coolant temperature sensor failure; Air temperature sensor failure; Hall sensor failure; Poor contact of engine control unit or damage of internal circuit, etc.

4. Electronic control system failure

The electronic control system mainly determines the injection quantity and ignition advance angle of gasoline according to the engine working condition and vehicle driving condition. The system is mainly composed of sensors, actuators and ECU. Sensors collect all kinds of data in engine operation and send them to ECU for processing, so as to better control the fuel injection and ignition of the engine. If the sensor data collected by ECU is deviated, it will lead to deviation in ignition or fuel injection, and the engine will not work normally. The control computer is the core component to control fuel injection and ignition, and the common fault of the control unit is the damage of internal circuit or poor contact.

5. Mechanical structure failure

(1) Piston connecting rod mechanism and engine block

Common faults of crank-connecting rod mechanism include: piston ring is damaged or lost elasticity, carbon deposit in piston ring groove, carbon deposit in cylinder, bending deformation of connecting rod and so on. These faults will also lead to unbalanced power of each cylinder and engine jitter.

(2) Valve train

Common faults of valve train include: incorrect timing belt installation leads to inaccurate valve timing, too much carbon deposit in valve working area leads to lax valve closing, inconsistent cam wear leads to inconsistent air intake of cylinders, and valve spring fracture leads to lax valve closing.