Several tests can be done to test an electronic ignition coil, including a standard coil test, primary circuit switching test and ignition coil resistance. These tests will test the resistance felt on the ignition coil when it is connected to an outside power source.Know More
To perform a standard ignition coil primary resistance test, the ignition should be off in the car. Once the two low voltage coil terminals are disconnected, the resistance should remain between 0.3 and 1 ohms.
A switching test uses a 12 VDC test lamp. A small straight pin should be inserted into the wire that runs the negative coil to the TFI module. The pin can then be connected to the lamp. If the lamp flashes, more circuit tests need to be performed. If the light simply lights up, a wiring harness test should be performed. If the light does not come on at all, the continuity of the primary circuit should be tested.
Ignition coil resistance tests are used on the secondary aspects of the ignition coil. These tests should be performed with caution because the circuits of the secondary part of the ignition can have very high voltage. These tests should only be performed if there was inconclusive evidence in any of the primary tests.Learn more in Car Parts & Maintenance
The signs of a failing ignition coil include backfiring, starting issues, lowering gas efficiency, engine misfiring, vehicle stalling and worn out spark plugs. The most common symptom of a faulty ignition coil is when the car runs for a while and the engine dies abruptly. This happens when the ignition coil or module becomes too hot.Full Answer >
Ignition coil failures are caused by worn out spark plugs that fail to transmit electronic signals in a functional and fluid manner. This creates a disruption in the regular flow of power across the ignition coil and makes the engine lose power. It is less common but still possible that the rotor the ignition coil rests on breaks and reduces the function of the power circuit.Full Answer >
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.Full Answer >
In order to test the spark, pull the spark plug from the engine, and then start the car. There should be a bright blue spark between the electrodes every time the cylinder fires, provided that there is enough voltage reaching the spark plug. The coil is likely to be faulty if there is no spark.Full Answer >