Your vehicle’s ignition system is responsible for igniting the combustion process in your engine, allowing your engine to run. There are several common components in every ignition system. These include:

  • Ignition coils
  • Ignition High Tension leads (for older cars)
  • Spark plugs
  • Ignition switch
  • Battery
  • Distributor unit
  • Ignition Points (for many pre 1980 cars)
  • Ignition capacitor or condensor

If any of these components malfunction, your engine may:

  • struggle to start
  • not start at all
  • misfire at idle
  • misfire under acceleration
  • misfire under light load or cruising speed
  • use more fuel
  • blow black smoke out the exhaust
  • produce more emissions (green house gases)
  • have less engine power
  • cause damage to expensive exhaust components such as the catalytic convertor or oxygen sensor
  • cause a popping or cracking noise or engine back fire


Faulty Ignition Switch

The ignition switch is controlled by your keys or via a button in push-to-start on most vehicles. If your ignition switch is faulty, your vehicle may struggle to start. Common signs of ignition switch damage include:

  • The switch being hot to touch – this can be caused by overheating in the wires and terminals that control the ignition switch
  • Your vehicle should have four levels of ignition; off, accessory, on and start. If your vehicle skips any of these levels, it is likely a fault in the ignition switch. Your dashboard lights should all turn on when your vehicle is in the “on” position.
  • Your immobiliser circuit may be faulty due to not being able to detect the “rolling security codes” between your key FOB and the induction aerial circuit often in the ignition key barrel.


Faulty Spark PlugsSpark Plug

The role of your car’s spark plugs is to create an electrical spark, igniting the fuel in your engine and allowing your engine to start. Over time, spark plugs can become worn, losing effectiveness and affecting your vehicle’s ignition system. Symptoms of faulty spark plugs include:

  • Increased fuel consumption due to fuel not igniting properly.
  • A misfiring engine while driving.
  • Your vehicle struggles to start or doesn’t start at all.


Faulty Ignition Coil

The purpose of the ignition coil is to amplify the power supplied by the battery, giving your spark plugs the necessary amount of energy to ignite the air / fuel mixture. Some vehicles only contain one ignition coil, whereas others will have several, often connected to each individual cylinder. Ignition coils are only found in petrol vehicles. There are several common symptoms of faulty ignition coils. These include:

  • Problems starting your engine. The ignition coil cannot supply the necessary amount of energy to the spark plugs.
  • Your engine is stalling, particularly when it the engine returns to idle (around 750 rpm or lower with an engine at operating temperature).
  • The engine has to work harder when an ignition coil is faulty, often resulting in a louder engine and increased fuel consumption.
  • The engine shakes or vibrates more at idle
  • The engine lacks power (as it is running on less cylinders)
  • A “ticking” noise can be heard from the ignition coil while the engine is running, indicating that the ignition spark energy may be tracking outside of the ignition coils insulation.


Car Battery Problemscar battery test

Sometimes, ignition-related problems can be attributed to a car battery that is due for a replacement. Over time, the battery will lose its ability to hold a charge as efficiently, resulting in it going flat more often. When the battery is flat, the engine will not start.

For more information about batteries, visit our battery replacement page.

Ignition System Servicing in Hamilton

If you suspect your vehicle has a fault in its ignition system then we can help! At Grimmer Motors, our qualified, experienced and skilled mechanics are trained to use the latest in electronic diagnostic equipment to quickly find the source of your engine problems, saving you time and money. We can then provide reliable, high-quality replacement solutions in order to get your vehicle running correctly.

We provide reliable ignition system diagnostics and services for all vehicles, regardless of their make and model. Contact us today to book your appointment.


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