The Car Ignition Coil Always Burns Out, Which Is the Reason?

Sep. 19, 2020

1. Principle of the ignition coil

It is composed of the main coil, a secondary coil, a magnetic core, a switching transistor, and other auxiliary components. The main coil is charged by a battery, the secondary coil is discharged by a spark plug to ignite, and the transistor is responsible for switching. The charging time is controlled by the battery voltage and the engine speed to ensure that the energy of each charge is consistent. The ignition coil has two types: 3-wire and 4-wire. The 3-wire is the power supply positive, negative, switch control (ECU command), and the 4-wire has one more ignition detection. The wire can detect whether the spark plug is ignited (whether there is a discharge current in the secondary coil).

To put it simply, the ignition coil is a transformer, which increases the voltage of tens of volts to tens of thousands of volts, but the voltage input to the primary coil is provided by an electronic igniter.

2. Reasons for burnout of car ignition coil

Ignition coil burnout is mainly caused by the aging and breakdown of the insulation layer or the damage of the switching transistor. The large gap between the spark plugs will cause the main coil to load, generate heat, and the insulation layer will age quickly. The small gap between the spark plugs will cause the secondary coil to discharge current, heat, and insulation. Faster, the assembled ignition coil may have a short life due to poor insulation material durability, the large internal resistance of the coil, high heat generation, and low-quality tertiary tube.

Auto Ignition Coil

Auto Ignition Coil

If it is always burned out, it will burn out soon after replacement. What is the reason? Here are some of them:

1. First look at the problem of the generator. If the power generation is too high, the ignition coil will burn out if the load is too heavy, but if the power generation is really too high, the body electrical appliances, such as light bulbs, will often be damaged; of course, The quality of the accessories is not ruled out, so it is best to measure the power generation first.

2. The spark plug gap is too large, adjust the gap or replace the spark plug;

3. The gasoline quality is not good, try changing to higher-grade gasoline;

4. The cylinder compression ratio is wrong, adjust the compression ratio;

5. If there is a program failure on the computer board, you can go to the repair shop to test the car with a computer and clear the error message. If it still doesn't work, there may be a problem with the car's transmission.

6. The power supply voltage is unstable;

7. The resistance of the high-voltage line is abnormal, replace the high-voltage line;

8. There is a short circuit phenomenon in the secondary;

9. The primary current of the ignition controller is too high, causing the ignition coil to overheat;

10. It does not work well when subjected to high temperature and high-pressure waves;

11. It is very likely that the coil itself is a problem, you can try another brand;

12. The igniter integrated block works poorly;

The auto ignition coil itself is a transformer, which is like the transformer in household appliances. When the voltage changes within the specified range, the transformer will not be burned. Usually, the burning of the transformer occurs when the transformer is overloaded This situation is caused, so when solving this problem, we must try to find out the cause of excessive load or component aging.