Ignition Systems

At Universal Motors our fully equipped workshop in Thomastown, provides Ignition system diagnosis, repairs and replacement for all makes and models. All our car repairs come with a minimum 12 month/20000km warranty.

An ignition system is an array of components that are all involved in the process of igniting the air/fuel mixture in an internal combustion engine. Since there are two main types of internal combustion engines, there are also two main type of ignition systems and then a handful of other subtypes. Spark-ignited internal combustion engines can be broken down into magneto-type ignition systems and spark and coil systems, while diesel engines rely on compression to ignite the air/fuel mixture.

Ignition System Components

Since there are a few different types of ignition systems, not every engine has the same ignition system components. The two main types of ignition systems are spark-ignition and compression ignition, and there are also a number of different types of spark-ignited systems.

Magneto-type Ignition System Components

Magneto-type ignition system components typically include:

  • a high tension magneto
  • a condensor
  • one or more contact breakers (sparking plugs)
  • a distributor

In basic magneto-type ignition systems, the high tension magneto generates an electrical current that passes through a contact breaker (spark plug) in order to generate a spark and ignite the air/fuel mixture. These systems were popular in the early days of the automobile, but they are no longer used in automotive applications. Small engines, like those found in lawn mowers, often use these systems due to the fact that no battery is required for the ignition process.

Switchable Ignition System Components

Switchable systems are hybrids, so they typically included:

  • a magneto
  • one or more dry cell batteries
  • a coil
  • a distributor
  • two sets of spark plugs

One of the main drawbacks of magneto ignition systems is that the timing is fixed. In order to help deal with that situation, while not giving up the perceived reliability of the magneto, some vehicles were equipped with switchable systems. These ignition systems were hybrids of magneto and coil ignition, and they typically allowed the driver to switch over from coil to magneto after the vehicle was already started up and moving.

Spark plugs are a component of the ignition system that must be changed regularly. Not replacing spark plugs in time can cause further costly repairs including having to replace ignition coils.

  • Common Igniton system faults include:
  • Failure of the engine to start easily,
  • misfiring,
  • poor acceleration
  • Poor fuel consumption
  • Excess emissions

Your car’s ignition system has to work in perfect unison with the rest of the engine and ignite the fuel mixture at exactly the right time so that the expanding gases as a result of combustion maximise power. Power will decrease and fuel consumption will rise if the ignition system fires at the wrong time causing an increase in emissions.

Modern engine management systems also incorporate the ignition system by controlling spark timing which results in optimised performance and emission levels. Most modern cars have a direct ignition system which uses an ignition coil for each cylinder. The ECU fires the coil at the correct time using references from various sensors.