What Causes Misfiring in an Engine?
2 Answers
Reasons for engine misfiring: 1. Excessive wear gap in engine cylinder liner and piston rings; 2. Fuel injector wear leading to poor fuel atomization; 3. Issues with the engine control unit (ECU); 4. Problems with the spark plugs in the cylinder. Engine misfiring, also known as cylinder misfire or engine miss, refers to a fault where one or several cylinders in the engine fail to work or work insufficiently. Symptoms of misfiring: 1. Abnormal engine operation or insufficient power; 2. Uneven engine operation with rhythmic shaking; 3. Black smoke and loud noises from the muffler. Hazards of misfiring: 1. Decrease in engine speed and power; 2. Increased fuel consumption and emission pollution; 3. Accelerated wear of moving parts, shortening the service life of lubricating oil.
Misfiring frequently occurs in vehicle engines, and I've seen it many times, mainly due to issues with the ignition system, such as aging or damaged spark plugs failing to produce sparks, or faulty ignition coils affecting specific cylinders. Next are fuel system problems, like clogged or carbon-fouled fuel injectors leading to insufficient fuel supply, or low fuel pump pressure. On the mechanical side, a damaged cylinder head gasket causing insufficient compression ratio, or worn piston rings leaking gas, can prevent the cylinder from burning properly. Electronic control issues should not be overlooked either, with sensors like the crankshaft position or oxygen sensors misleading the engine control unit. Additionally, vacuum line leaks causing an imbalance in the air-fuel ratio are also common factors. For prevention, I recommend checking spark plugs and fuel injectors every 50,000 kilometers and replacing them promptly. If you feel shaking while driving, seek repairs as soon as possible.
