What does automobile engine backfire mean?

The normal operation of motion force is divided into four steps: 1. Entrance 2. Compression 3. Op 4. Exhaust tempering. Generally speaking, after the piston does work, the burnt exhaust gas is discharged from the exhaust pipe. However, due to some fault, the exhaust valve has been closed and the exhaust gas cannot be discharged. In other words, there is no need to rush to exhaust! Then the exhaust gas will be discharged from individual cylinders in the cylinder head, crankcase, carburetor, throttle and other places, which is what we often call "backflow". Tempering means that the mixture burns outside the combustion chamber before entering the combustion chamber. Most of these reasons are that the ignition timing of the engine is inaccurate, the engine is in poor working condition, the temperature in the cylinder is too high, and the valve seal is not tight. During tempering, the blasting sound and explosion sound in the engine room can be clearly heard. This situation is very dangerous, and the intake branch pipe is seriously blown up. If this happens, it is recommended to let professionals handle it. Engine tempering is actually intake pipe tempering: 1. The tempering of intake pipe is due to insufficient oil supply and too thin mixture; 2. If the mixture is too lean, the combustion speed of the mixture will slow down and the combustion will continue until the end of the exhaust stroke with the intake valve open. The fresh mixture will be ignited when it meets the combustion gas that is not completely discharged from the cylinder, and it will be ejected from the air inlet through the intake manifold, resulting in backfire. 3. If the intake pipe backfires, the engine body will shake seriously, the exhaust pipe will explode, and the engine power will drop seriously, which is mostly caused by inaccurate ignition; 4. Due to the disorder of ignition, when a cylinder is in the intake stroke and the intake valve is opened, the intake pipe backfires just when the spark plug of the cylinder is ignited.