The common faults of ignition coil are: Damaged by external forces and burnt due to excessive current. If the ignition coil is damaged, the ignition system will not work and the engine will not be able to start. Another fault is inevitable, which is caused by the aging of ignition coil.

The ignition coil fails in several situations

1. An individual cylinder does not work without spark, lead to shake when idling and poor acceleration when refueling.

2. The electrical leakage of ignition coil, idling engine wobble sometimes have or sometimes not, but poor acceleration when refueling

3. When accelerating，sometimes resulting in engine wobble because the electricity supply has been cut off.

4. If the ignition coil has a fault, the car can’t start.

Causes of ignition coil failure

For conventional ignition system. What may happen to ignition coil after the vehicle is stopped but ignition switch is forgotten to turn off ?  What could possibly go wrong with the ignition coil?  If this occurs, the primary and secondary winding of ignition coils will be short circuit, open circuit, and grounding. For the primary winding. The heating will be severe and the ignition coil will be burnt when primary current is too high.

From conventional ignition system point view, the magnitude of primary current is inversely proportional to the engine speed. The primary current is high when a car at low speed. For example, when a loaded car climbs the hills at low speed with wide open throttle, which shows the engine torque is maximum. When the rated torque of engine at low speed, resulting in more closure time of breaker contact point and more high current.

The aging of ignition coil

For the secondary winding. When the primary current is cut off, the secondary winding induct high voltage electromotive force, so that the ignition coil is easy to burn down after long use. Generally, the ignition coil will be replaced once for 100,000 kilometers. When the engine is running, the ignition coil often produces tens of thousands of volts of high voltage current. The ignition coil works in a high temperature, dusty and vibrating environment for a long time, inevitably causing aging or even damage. If the ignition coil is not replaced in time, it will have an impact on the engine's working performance, obviously, it is crucial to know the aging of ignition coil: Open the engine compartment and observe whether the ignition coil has the symptoms of gum overflow, burst, and corrosion of connector and high pressure nozzle. If ignition coils need to be replaced because of aging, then even if only one fails, it is better to replace them all, as the others are in similar condition. If only one or two ignition coils fail, while the others are not affected and in good condition, then you just need to replace the faulty one.