What should be checked for abnormal idling jitter of automobile engine?

Dirty air filter: The air filter is designed to protect the engine from wear and tear, and it is usually replaced at about 10000 km. If it is not replaced in time, the engine will shake due to insufficient air intake, which can be solved by replacing the filter element.

2. High-voltage line break: High-voltage line break refers to the break of conductor core of high-voltage line, which can affect ignition and cause engine jitter. You can use a multimeter to measure the resistance, and change it to a resistance that is obviously several times larger.

3. There is something wrong with the spark plug: the spark plug has a service life. After exceeding 30,000-40,000 kilometers, the ignition efficiency is obviously reduced, which may affect the ignition. This is the most common fault. Just replace all spark plugs.

4. Abnormal water temperature: The working temperature of the engine is within the normal range. When the water temperature is high, the ignition time will be early, the oil-gas mixing ratio will change, the oil viscosity will become thinner and the lubrication performance will become worse. Common fault causes include insufficient antifreeze, thermostat not turned on, fan not turning, jitter caused by inaccurate temperature control switch, etc. All the above faults can be eliminated.

5. Nozzle blockage: The gum in gasoline will block the fuel injection hole of the fuel nozzle, thus causing the fuel injection quantity of each nozzle to be inconsistent, resulting in the inconsistent work of each cylinder and engine jitter. The solution is to take it down and clean it.

6. Carbon deposit and oil dirt blockage: Throttle, idle valve and air intake will be blocked by carbon deposit and oil dirt after a period of use, which will affect the idle stability and cause jitter. It can be solved by checking and cleaning the above parts with cleaning agent without disassembly and cleaning. 8。 Cylinder depression: the engine has three cylinders, four cylinders, five cylinders, six cylinders and eight cylinders. If a cylinder is not easy to use, there will be a lack of cylinder and engine jitter.