What Are Some Symptoms of a Bad Ignition Coil?

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Symptoms of a bad ignition coil include backfiring, bad fuel economy, and stalling and starting issues. Before the ignition coil is replaced, the engine will need to be properly diagnosed to ensure it is the root of the problem.

The ignition coil is located inside the distributor and is responsible for taking power from the alternator and delivering it to the plugs. When these units fail, the spark plug wires can overload, causing all of them to fail intermediately. In order to ensure the engine remains healthy, a faulty coil should be replaced. The following instructions explain how to do so.

  1. Disconnect the battery
  2. The ignition coil deals with a lot of electricity and battery must be disconnected before replacing it to avoid damage to the engine and shock.

  3. Locate the coil
  4. The coil is located inside the distributor. The location of the distributor depends on the make and model of the vehicle.

  5. Unplug the coil
  6. Disconnect the wire that leads to the generator and to the cap.

  7. Remove the cap
  8. Loosen the screws and remove the cap from the distributor. Once off, remove the coil.

  9. Install the coil
  10. Replace the coil with the new unit. Reinstall the cap and distributor wires, and reconnect the battery. Once everything is connected, start the car and check the coil.