What is the situation of engine jitter and cylinder shortage in hybrid electric vehicle, and how to solve it?
First, engine jitter caused by ignition system.
1. Spark plug
The first problem of car cold start is low temperature. The temperature in the engine is not enough, and the temperature of fuel and lubricating oil is not enough. Therefore, more fuel should be injected during cold start to meet the power requirements. The larger the gap between spark plugs, the smaller the ignition energy. Fuel atomization is not good at low temperature, which requires high ignition energy. When the automobile is used for a long time, the ignition gap of the spark plug is easy to become larger, which leads to the decrease of ignition energy. The ignition gap and time control of spark plug will be different, but ECU can't diagnose this deviation and still treat it equally, which leads to the error between practice and theory. The power generated by some cylinders is too small, which affects the dynamic performance and makes the car shake.
2. Ignition coil
Ignition coil is the energy source of spark produced by spark plug, and its work directly affects the quality and completion of ignition. ECU uses knock sensor to identify the working state and knock condition of the whole ignition. Special instruments can be used to talk to ECU, so as to know the specific location of the fault. In maintenance examples, it is often found that the air under the ignition coil can not be removed because of the careless sealing condition of the ignition coil when installing it, and the gas expands when heated, which makes the ignition coil pop up, causing artificial engine jitter and so on.
Second, the oil supply system failure leads to jitter.
1. Fuel injector
Blockage/leakage/blockage of fuel injection nozzle will affect fuel injection quality. When one or more of them deviate, the oil-gas mixing ratio of each cylinder is inaccurate, and the power between cylinders is inconsistent, resulting in jitter.
2. Fuel pump
Faults of fuel pump, fuel filter, oil pressure regulator and other components of oil supply system cause oil pressure fluctuation, which leads to unstable engine operation.
Third, the engine jitter caused by the intake system.
1. Intake pipe and valve
If there is carbon deposit in the valve and intake of the engine, ECU will make a wrong judgment, because carbon deposit can absorb a proper amount of fuel. When the engine is turned off, there will always be some valves open at this time, and carbon deposits will adhere to the working surface of the valves, which will harden after cooling for one night or more.
2. Air filter, air flowmeter, throttle valve and air inlet connecting hose.
The air filter element is blocked due to long-term use, which leads to small air intake, aging damage of air intake hose or air leakage at various joints, data deviation of air flowmeter, damage of throttle sensor and so on. These factors will cause the control unit ECU to affect the mixture, resulting in engine jitter.
Fourth, the engine mechanical parts caused by jitter.
After the engine is used for a long time, the gap between each cylinder liner and piston will be different, that is, some gaps are large and some gaps are small. In cold start, without good oil lubrication, the cylinder with large gap is easy to leak some high-temperature gas from the gap, thus reducing power output.
Five, the water temperature sensor failure leads to jitter.
The water temperature sensor is one of the important bases for the computer to judge the working condition of the engine at that time.