What Causes a Misfire?
The spark that jumps across the gap between the plug’s electrodes ignites the fuel mixture and releases the explosive power in the fuel. If there’s no spark or the spark is too weak to ignite the fuel, the engine misfires, looses power, wastes fuel and pollutes. Misfires are bad news because unburned fuel passes right through the engine and into the exhaust. This increases emissions and also causes the catalytic converter to run hotter than normal. A really bad misfire may even damage the converter. Every engine misfires occasionally, but if the spark plugs are worn or fouled, or the ignition system can’t deliver enough voltage for reliable ignition, misfires may cause hard starting, rough running, hesitation, increased fuel consumption and elevated hydrocarbon (HC) emissions. It doesn’t take many misfires to make a vehicle fail an emissions test. What Type of Plug Shall I Use? One way to prevent misfires is to make sure the engine has a good set of spark plugs. These can be standard p
