Miata 1990-1997

Spark Plug Wires

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Removal & Installation



Specific to:

Mazda Miata 1990-1997

Replace the spark plug wires one at a time when installing a new set so there will be no mix-up. The longest cable should be replaced first. Make sure that the boot is installed firmly over the spark plug. The wire routing should be exactly the same as the original. Insert the nipple into the tower on the distributor cap and/or coil. Repeat the process for each wire.

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Fig. Remove plug wires by grasping its boot, not the wire, and, while twisting slightly, pull straight upwards

Testing



Specific to:

Mazda Miata 1990-1997


NOTE
Only test one spark plug wire at a time. When the check is complete return the plug wire to its original location. If the wire is defective and more wires are to be checked, mark the wire as such, return it to its original location, then inspect the other wires. Once all of the wires are checked, replace the defective wires one at a time. This will avoid any mix-ups.



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Fig. Testing the spark plug wire resistance through the distributor cap with an ohmmeter

  1. Remove the distributor cap from the distributor assembly.
  2.  
  3. Visually inspect the spark plug wires for burns, cuts or breaks in the insulation. Check the spark plug boots and the nipples on the distributor cap and coil. Replace any damaged wiring.
  4.  
  5. Inspect the spark plug wires to insure that they are firmly seated on the distributor cap.
  6.  
  7. Disconnect the spark plug wire thought to be defective at the spark plug.
  8.  
  9. Using an ohmmeter, measure the resistance between the distributor cap terminal and the spark plug terminal.
    NOTE
    Make certain that a good connection exists between the distributor cap and the spark terminal. Never, under any circumstances, measure resistance by puncturing the spark plug wire.

  10.  
  11. If the measured resistance is less than 16k ohms per 3.28 feet (1m) of wire the wire is good. If the measured resistance is greater than 7000 ohms per foot, the wire is defective and should be replaced.
  12.  

 
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