The purpose of the Ignition Coil, or Ignition Module, is to produce spark to your spark plug in order to start the engine for your machine. You may need to replace your ignition coil if you are getting no spark when attempting to start your machine. When diagnosing the source of your ignition problem, determine if the result is from a faulty spark plug, or ignition coil. If the ignition coil and spark plug can produce spark when disconnected from the wiring system, the issue may be in the wiring system.