The spark plugs … Don’t take them lightly
The spark plugs are a vital part of the operation of the vehicle. Poor performance of your vehicle can sometimes be traced to the plugs. If points and plugs are clean and gapped; if the engine’s timing is on the mark; if the wiring is in good repair, and if the battery and generator are functioning as they should, the defensive driver has a safe and reliable motor vehicle.
“It is wise to let your mechanic check and double check your spark plugs every few thousands of miles,” advises Keith Austin, auto electrician. They will last longer if they can be gapped periodically, and a check of this will reveal any malfunction in the carburettor that may lead to poor gas mileage and impeded performance.” According to Austin, the ignition points should be adjusted at regular intervals. When these contacts, which transmit the current to the spark plugs, become a few thousandths of an inch out of position, they burn out quickly and mileage and performance will decline.
Take note of these pointers:
1. Engines which misfire are often caused by leaking spark plug wires, so visual inspection could reveal the problem.
2. The spark plug jacket may be damaged by engine vibration, particularly at the plug and boots.
3. The problem could also be a hot engine compartment or spilled fluids or battery acid, multiple disconnections and reconnections or rodents building a large family.
4. A test could include the use of a jumper wire grounded to the metal shank of a screwdriver along the length of each wire and all around at the coil and plug boots. This will often produce an arc from the wire to the screwdriver. Afterwards, take a look at the wires under good lighting. If they are damaged by the abrasion, oil-soaked, cut, burned from contact with the exhaust, or have a dried-out look with heat cracks, it will be no surprise to see arcs in the dark.
Here is how the spark plug works:
The spark plug wires carry the high voltage electricity produced by the ignition coil to the terminal of the spark plug. Once at the plug, electricity travels to the other end of the plug and jumps a gap between electrodes to produce the ‘spark’ that ignites the fuel mixture. High voltage electricity travels easily along a path than a pair of electrodes in the spark plug. Some plugs have an outer jacket to resist cuts. If that outer jacket is damaged, the electricity may leak out to follow the easier path. High voltage electricity produces radio waves which can cause interference with all types of on-car electronic devices, from sensors and computers to radios and other entertainment systems. “An insignificant length of solid wire can create all kinds of problems,” stated Keith Austin.