Here's how to check for spark, using a spark tester and an inline spark tester:
Method 1: Using a Spark Tester (Most Reliable)
1. Safety First: Disconnect the negative (-) terminal from the battery. This is crucial to prevent electric shock.
2. Locate the Spark Plug Wire: Identify the spark plug wire you want to test. It's usually a high-voltage wire connected to a spark plug.
3. Remove the Spark Plug Wire: Carefully remove the spark plug wire from the spark plug.
4. Attach the Spark Tester: A spark tester has a clip that attaches to the spark plug wire and a metal probe that should be grounded (touching a clean unpainted metal surface on the engine block).
5. Have Someone Crank the Engine: Ask someone to crank the engine (turn the key to the "start" position) while you observe the spark tester. You should see a bright, consistent spark jump across the gap in the tester. If the spark is weak or intermittent, there's a problem with the ignition system.
Method 2: Using an Inline Spark Tester (Less Reliable, but convenient)
An inline spark tester plugs into the spark plug wire, eliminating the need to remove the wire completely. It has a built-in gap for the spark to jump across. Instructions vary depending on the specific tester, but the general procedure is:
1. Safety First: Disconnect the negative (-) terminal from the battery.
2. Install Inline Spark Tester: Connect the inline tester into the spark plug wire. Ensure a good connection.
3. Ground the Tester: Some inline testers require a separate ground connection. Check the manufacturer's instructions.
4. Have Someone Crank the Engine: Ask someone to crank the engine. Observe the spark.
Interpreting the Results:
* Strong, consistent spark: Indicates a healthy ignition system.
* Weak or intermittent spark: Suggests problems with the ignition coil, distributor (if equipped), ignition control module (ICM), spark plug wires, or the spark plug itself.
* No spark: Points to a more significant issue, potentially in the ignition coil, crankshaft position sensor, camshaft position sensor, ignition module, or a broken wire in the ignition system.
Troubleshooting if no spark:
If you have no spark, you'll need to systematically check components. This could involve testing the ignition coil with a multimeter, checking the continuity of the spark plug wires, inspecting the distributor cap and rotor (if applicable), and possibly testing the crankshaft position sensor or camshaft position sensor. This requires more advanced diagnostic tools and knowledge.
Important Considerations:
* Spark Plug Condition: Even with a good spark, worn-out spark plugs can prevent proper combustion. Inspect the plugs; replace if necessary.
* Professional Help: If you're not comfortable performing these tests or if the problem persists after checking for spark, consult a qualified mechanic. Ignition system issues can be complex.
Remember safety first! Working with high voltage can be dangerous. If you are unsure about any step, seek professional assistance.
