Close up of car stop start system with copyspace on the left, 3D illustration

Ignition System Diagnostic Repair

SIGNS AND SYMPTOMS OF IGNITION FAILURE

In this article we’ll explore the key components of a standard Ignition system and some of the reasons things stop working.

A vehicle’s ignition system is responsible for activating the reactions in an internal combustion engine or more simply put, it turns the car on

This is accomplished by a series of parts known as ignition components that work with one another. These components vary by the type of ignition system inside the vehicle.

Most cars, trucks, and SUVs will have one of three types of ignition system. Either Distributor-based, Distributor-less, or Coil-on-plug.

Battery and coil ignition systems rely on mechanical parts to pass a high current through a coil which then causes the ignition. Electronic ignition systems use a similar method, except there are no mechanical components in use and instead rely on sensors to activate the coil.

Despite the differences, the following components are usually evident in both systems:

  • Coil
  • Spark plugs
  • Spark plug wires
  • Ignition module
  • Distributor rotor

When one or more of the components is faulty, or begins to fail, the car’s entire ignition system is affected. These effects look different and will depend on the component that has failed. There are signs you can look for that can point to one or more component failures in your vehicle’s ignition system.

IGNITION LOCK CYLINDER

The ignition lock cylinder is the first component of an ignition system that is activated since it does so when your key is inserted and turned. Signs of a failed ignition lock cylinder include failure to start the car and trouble using your car keys. You may even experience some grinding when turning the key or the key not turning.

BAD IGNITION COIL

A coil takes the battery voltage and amplifies it to a voltage that is high enough to jump a gap. A coil that has gone bad will not be able to convert energy from your car’s battery into the voltage it needs to ignite the engine. A spark plug not receiving enough voltage could be a sign of a faulty coil, along with engine misfiring, difficulty accelerating, and poorer fuel performance than usual can also mean the coil has gone bad.

FAILING DISTRIBUTOR ROTOR AND CAP

The distributor rotor and accompanying cap orders the voltage to go to the right spark plug in the right order. The ordering of the voltage is a metal on metal connection and does wear over time. When this part fails it makes the car impossible to start or causes the engine to misfire. Drivers may also notice strange noises coming from under the hood, since parts of the engine will not get enough voltage to continue the chain of ignition.

SPARK PLUGS

Spark plugs do just what their name implies, they ignite a spark that then creates the reaction inside your engine. Spark plugs that are dirty will cause misfiring, low gas mileage, and shaky idling. Broken or damaged plugs will lead to hard engine starts and poor acceleration, so drivers should never let their vehicle pass the 30,000 mile mark without giving them a look.

SEE SOMETHING, DO SOMETHING

Ignition systems should be visually inspected every year, and if any of the above symptoms begin to arise in your car then don’t wait to get them checked out. Since your vehicle’s engine is completely dependent on the ignition system, ignoring problems now can lead to even more serious, and therefore expensive, repairs in the future.

Getting something like an ignition coil replaced for anywhere between $300-$500, which is nothing compared to the costs of replacing your engine. As long as you pay attention to your vehicle’s behavior, and make an effort to get it inspected annually, you have a good chance of catching a big problem while it’s still small.