What Causes a Cylinder Misfire?
2 Answers
Reasons may be caused by damage to external components, mainly involving parts around the combustion chamber such as valves, valve seat rings, valve guides, and spark plugs. Below are the relevant details: 1. Misfire Causes: A misfire occurs when the air-fuel mixture in the cylinder fails to ignite or ignites too late. Sticking or closing of the fuel injector coil in the next working cycle due to excessively high self-induced voltage can also cause misfires. 2. Precautions: A misfire in one cylinder of the engine is a serious issue that can reduce transmission efficiency and potentially damage the engine. If abnormalities are detected, prompt repairs are necessary.
Seeing a misfire in one cylinder, I've encountered this issue several times while repairing cars. The most common cause is spark plug problems, such as burnt electrodes or excessive gaps, which prevent the spark from jumping. Faulty ignition coils are also a frequent issue—they supply power to the spark plugs, and if the coil is aged or damp, insufficient electricity can lead to ignition failure in the cylinder. Fuel system problems are unavoidable too, like clogged fuel injectors or low fuel pump pressure, which disrupt timely fuel supply and cause engine shaking. Compression issues are also common—if piston rings leak or valve seals fail, inadequate cylinder pressure prevents proper ignition. Sensor malfunctions often occur as well, such as errors in the crankshaft position sensor, which sends incorrect signals to the ECU and disrupts ignition timing. In short, always start troubleshooting from the simplest causes and don’t overlook routine maintenance—inspecting ignition components every 50,000 km can save major trouble.
