The ignition system produces the high voltage required to create an electric arc strong enough to jump the gap of the spark plug. This electric arc, or spark, ignites the air / fuel mixture in the combustion chamber. The ignition system is also responsible for providing the spark at the appropriate time during the compression stroke.
The ignition system converts the 12 volts (V) from the vehicle’s battery to over 20,000V. The high voltage is needed to push the electrical current across the spark plug to create the spark. The spark ignites the air fuel mixture. If the voltage is not high enough to push the current, no spark, or a weak spark occurs, causing a misfire.
Spark plugs are an important part of the engine’s ignition system and are responsible for igniting the air/fuel mixture in the engine cylinders. Over time, spark plugs can become worn and covered in carbon. Replacing spark plugs at the recommended interval helps to keep the engine running smoothly and efficiently.
For an engine to operate efficiently, the air / fuel mixture must properly blend. Too much air and not enough fuel causes the mixture to be lean. Too much fuel and not enough air causes the mixture to be rich. Both cause the engine to not operate at its full potential. The ideal air to fuel ratio for gasoline engines is called the stoichiometric ratio. At this ratio of 14.7 parts air to 1 part fuel, or 14.7:1, the oxygen and fuel consume completely, and the engine produces its maximum power.