360 Motorsport LTD

Testing Ignition Coils on an Engine

Testing the ignition coils in your Performance Japanese car can be done using a few different methods. Here’s a step-by-step guide to help you through the process based on testing Nissan coils:

Tools and Materials Needed:

  • Multimeter (with Ohm measurement capability)
  • Spark tester (optional but recommended for a more comprehensive test)
  • Basic hand tools (e.g., screwdrivers, socket set)

Steps to Test Ignition Coils:

  1. Safety First:
    • Ensure the car is off and the keys are removed from the ignition.
    • Disconnect the negative terminal of the battery to avoid any electrical shorts or shocks.
  2. Locate the Ignition Coils:
    • The ignition coils are usually located on top of the engine, connected to the spark plugs. For the Skyline BNR32 GTR, they are likely under a coil cover.
  3. Remove the Ignition Coils:
    • Carefully disconnect the wiring harness from each ignition coil.
    • Use the appropriate tools to remove the bolts securing the coils in place. Gently pull the coils out.
  4. Visual Inspection:
    • Check each coil for signs of damage, such as cracks, corrosion, or burn marks. Any visible damage usually means the coil needs to be replaced.
  5. Resistance Test with a Multimeter:
    • Primary Coil Resistance:
      • Set your multimeter to the Ohms (?) setting.
      • Place the positive (red) probe on the positive terminal of the coil and the negative (black) probe on the negative terminal.
      • Compare the reading to the manufacturer’s specifications (typically found in the service manual). A significant deviation means the coil might be faulty.
    • Secondary Coil Resistance:
      • Place one probe on the positive terminal and the other on the high-tension terminal (where the spark plug connects).
      • Again, compare the reading to the specifications.
  6. Spark Test (Optional but Recommended):
    • Reconnect the ignition coil to the wiring harness but leave the coil out of the engine.
    • Attach a spark tester to the ignition coil output (where it connects to the spark plug).
    • Ground the spark tester to the engine block.
    • Crank the engine and observe the spark tester. A strong, consistent spark indicates the coil is functioning properly. A weak or no spark suggests the coil may be faulty.
  7. Reinstall the Coils:
    • If the coils pass the tests, reinstall them in the reverse order of removal.
    • Reconnect the battery.

Additional Tips:

  • Swap Test: If you’re unsure about a coil’s condition and have a similar working coil, swap them and see if the misfire moves to a different cylinder.
  • Code Reader: Using an OBD-II scanner can help identify which cylinder is misfiring, allowing you to focus on specific coils.
  • Service Manual: Always refer to the vehicle’s service manual for specific resistance values and testing procedures.

If you find any ignition coil that fails the resistance test or does not produce a proper spark, it should be replaced. Ignition coils are critical components, and ensuring they are in good working condition is essential for optimal engine performance.