How does a spark plug wire work in an engine?
During normal engine operation, a coil or plug wire in a conventional mechanical or electrical ignition system works by first transferring a high voltage pulse from an ignition coil to a distributor. The distributor, cap, and rotor then work together to create an electrical connection between the coil wire and one spark plug wire.
Why do I need to ground the spark plug?
It is worth noting, on some vehicles you can cause issues with the ignition system by not grounding the spark plug. If you allow nowhere for the spark to travel, it can fry the ignition components. Without knowing exactly if your vehicle is one of those, it’s always a good choice to ensure the spark has some place to travel.
What happens if your spark plugs are not working?
If your spark plugs are not working as they should; your engine will produce a rough and jittery sound and your engine will stumble. Faulty spark plugs can cause the car to exhibit starting troubles.
How are spark plug wires connected in a distributorless ignition system?
In distributorless ignition systems, the spark plug wires connect the spark plugs directly to one or more coil packs. In distributorless ignition systems, spark plug wires connect each coil pack directly to one or more spark plugs. These plug wires are otherwise identical in appearance and function to other high tension leads.
What causes a spark plug to jump to the ground?
Heat damage – Engine heat can burn wire insulation and boots. A damaged boot can impede proper spark plug wire seating and performance. Wire insulation that’s damaged by head can allow voltage to jump to the ground rather than jumping the gap at the bottom of the spark plug.
Do you need to ground the spark plug when testing?
Yes you should ground the spark plug. In your case the spark plug was close enough to the block to still jump the gap. If the plug was far enough away from metal nothing would have happened. On a separate note. When testing for spark it is recommended to use a spark tester. Using a spark plug is a poor test of the ignition system.
How are ground electrodes used in spark plugs?
Double fine wire electrode (DFE) spark plugs apply a fine wire pin to the ground electrode in addition to a fine wire center electrode. A smaller electrode requires less voltage to jump the gap, resulting in fewer misfires, which translates to increased fuel economy and horsepower. A smaller electrode also reduces flame quenching.
What to do if your spark plug is bad?
Check the fuel system and/or stark timing. Weak sparks are orange or red and may be hard to see in daylight. If you did not see a spark, remove the coil wire from the distributor cap. Attach the spark tester to the distributor end of the coil wire. Crack the engine and check for a good spark at the spark tester.