Understanding the Pencil Ignition Coil System

　　Pencil coils are known for the electrical, mechanical, and thermal isolation between their magnetic cores, which are used to generate magnetic fields. The engine generally uses a mechanical double-speed ignition system, and the key to this system is the distributor. Contains a rotary cam drive, a set of breaker points, a condenser and a distributor cover. The distributor is connected to the spark plug and the ignition coil by wires. One of the general names of the ignition coil, called the pencil coil, is inserted into the spark plug insertion hole of the cylinder head.

　　A typical multi-coil ignition system can have one of several different configurations. In Chrysler, Toyota and many other imported cars, the coil is mounted directly on the spark plug. Many of these are thin "pencil" coils that extend down into grooves in the engine valve cover. The spark plug protrudes from the side of the cylinder head, and there is no space to install a coil at the end of each plug. Here, a single coil is installed on the valve cover and connected to the plug through a short plug wire.

　　Another important component of the ignition coil is the crankshaft angle sensor. It is an electronic device used in internal combustion engines to monitor the position or speed of the crankshaft. The engine management system uses this information to control the ignition system timing and other engine parameters. Before the electronic crankshaft sensor is available, the distributor must be manually adjusted to the timing mark on the engine.

　　The crankshaft sensor can be used in combination with a similar camshaft position sensor to monitor the relationship between the piston and the valve in the engine, which is particularly important for engines with variable valve timing. This method is also used to "synchronize" the four-stroke engine at startup, letting the management system know when to inject fuel. It is also commonly used as the main source for measuring engine speed in revolutions per minute.