What is the purpose of coil testing?
Ignition coils are a very important part of the ignition system, and can dramatically affect the engine’s performance when not functioning correctly. A failed coil can cause all sorts of problems, and testing them will ensure that your vehicle stays running in top condition.
How do you test if your coils are bad?
Some of the most common tell tale signs that a coil may be defective include:
- A rough idle.
- An unexplainably louder-than-usual engine.
- A noticeable lack of power.
- A significant drop in RPMs while accelerating for no apparent reason.
- A blinking or intermittently activating check engine light.
What causes coils to fail?
Coils fail for a variety of reasons including heat, vibration, or issues on the secondary side of the ignition system. Worn secondary ignition components such as spark plugs or wires can cause a coil work harder, require more voltage, and therefore significantly reduce the operating life of the coil.
Can a coil test good but be bad?
While it works to some degree, a major issue is that you are not able to simulate load, or measure the coil during operation, so weak coils that are not performing may still pass this test, but still be bad. Nonetheless, testing the coil’s windings for proper resistance can help you find potential problems.
Can you check an ignition coil with multimeter?
While ignition coils will generally last for the life of a vehicle, faulty spark plugs or spark plug wires can send irregular voltage surges through the ignition coil, causing the coil to burn out. You can test a 12-volt ignition coil for effectiveness by checking the resistance of its wire windings with a multimeter.
What happens when you test the ignition coil?
Regardless of how many coils your vehicle has, you’ll need some basic tools to properly test a coil: Ignition coils fail in 2 ways – either complete failure and lack of output, or intermittently, meaning, the coil gets weak, output gets low, or the coil sometimes works and sometimes doesn’t.
How to test an ignition coil axleaddict?
Testing an Ignition Coil for Voltage Leaks and Other Internal Faults 1 Connect the test spark plug to the output terminal of the ignition coil and ground the test spark plug. 2 On systems with more than one coil, remove the fuel system fuse to prevent the engine from starting. 3 Crank the engine, just enough to inspect the condition of the spark.
What kind of spark tester is used for ignition coils?
An ignition spark tester like OEM 25069 takes the place of a spark plug – is grounded to the engine and can easily show you whether a particular wire or coil is providing spark.
When to replace ignition coil with infinite resistance?
If your reading indicates infinite resistance, there’s an electrical open in the winding. Replace the ignition coil. If your reading is higher than the specification, there’s too much resistance in the winding. Replace the ignition coil.