How Does The Ignition System Work?

You walk outside and go to your vehicle. You put the key in, turn it, and your engine starts right up.

What just happened?

Well, what just happened is that your internal combustion engine just did its thing, and that thing is all dependent on the ignition system working properly.

So, how does the ignition system work? That’s what we are going to find out today.

The whole purpose of the ignition system is to generate a very high voltage from your battery to the spark plugs.  In truth your 12 volt battery does not have the power to start your car; that power must come from another source and that source is your ignition system.

When you turn the key, the current from your battery goes to the ignition coil.  This component is an electromagnetic device that gives you the voltage necessary to charge the spark plugs, and those spark plugs fire into the combustion chambers and ignite the fuel/air mixture in the engine.

The ignition system also consists of the distributor, which is a metal bowl that holds the central shaft, driven directly by the crankshaft. The bowl houses the contact-breaker points, rotor arm and a device for altering the ignition timing.  One spark to each plug and then the process is repeating thousands of times while the engine is running.

Also inside of that bowl is the distributor cap, a plastic that device that sends electrodes to the spark plug leads.

Finally, the current sparks across the gap in the plug, flows along a side electrode, through the body of the spark plug and engine, then returns to the coil to complete the circuit…and then the whole process starts again.

Repairing or replacing the ignition system is really not as complicated as it may sound.  Replacing the distributor is a matter of screws, and changing plugs is also a matter of unscrewing.  Considering how simple a job it is, it is amazing how much it will cost if a car mechanic does it.  At $75 per hour for labor it does not take long to rack up a few hundred bucks in cost, so the next time you need a relatively simply repair done, consider doing it yourself.

Come to All Import Auto Parts and find the replacement part you need. We carry hundreds of thousands of used parts, from transmissions to brakes to radios and yes, ignition systems. Then take the part home and install it yourself.  You will save hundreds of dollars and feel great when you finish.