What Are the Reasons for a Car Spark Plug Not Firing?
2 Answers
Reasons for a car spark plug not firing: 1. Improper spark plug gap adjustment: If the gap is too small, it limits the contact area between the spark and the air-fuel mixture; if the gap is too large, the ignition system may not provide sufficient voltage to create a spark between the electrodes. 2. Cracked spark plug skirt: High-voltage current leaks through the crack, preventing sparking at the electrodes. 3. Low spark plug insulation resistance: This phenomenon reduces the ignition voltage applied to the spark gap, weakening the spark or even completely disabling the ignition function. 4. Short circuit in the high-voltage wire: If the high-voltage ignition wire from the ignition coil to the distributor is short-circuited, the entire engine may fail to start; if the wire from the distributor to the spark plug is short-circuited, the spark plug in one cylinder may not fire.
My car's spark plugs aren't firing, and I've encountered this issue several times, mostly due to overall ignition system failure. The most common causes are aging spark plugs or excessive carbon buildup, leading to an overly large electrode gap that prevents spark generation, or damaged ignition coils failing to deliver high voltage. Poor contact or short circuits in the high-tension wires are also primary culprits. In older vehicles, distributor issues like cracked distributor caps or worn rotors may be to blame. Control-related causes include electronic control unit failures and interrupted signal transmission resulting in incorrect ignition timing. A dead battery or insufficient power supply can also cause circuit voltage to drop too low to generate sparks. Neglecting regular maintenance exacerbates these problems. It's advisable to routinely inspect spark plugs and circuits, and address any issues promptly to avoid starting difficulties or damage to other components.
