- Distributor cap and rotor: The distributor cap and rotor are responsible for distributing the electrical charge from the ignition coil to the spark plugs. If the cap or rotor is cracked, damaged, or worn, it can prevent the spark from reaching the plugs.
- Ignition coil: The ignition coil is responsible for creating the high voltage charge that is sent to the spark plugs. If the coil is faulty, it will not be able to create a strong enough spark to ignite the air/fuel mixture in the cylinders.
- Ignition wires: The ignition wires carry the high voltage charge from the ignition coil to the spark plugs. If the wires are damaged or corroded, they can prevent the spark from reaching the plugs.
- Spark plugs: The spark plugs are responsible for igniting the air/fuel mixture in the cylinders. If the plugs are worn, fouled, or damaged, they will not be able to create a strong enough spark to ignite the mixture.
- Electrical connections: The ignition system relies on a number of electrical connections to function properly. If any of these connections are loose, corroded, or damaged, it can prevent the system from working properly.
Troubleshooting
To troubleshoot the no-spark condition in your 1985 300ZX, you will need to follow a systematic process of elimination. Start by checking the distributor cap and rotor for cracks, damage, or wear. If the cap or rotor is faulty, replace it.
Next, check the ignition coil by measuring the resistance between the primary and secondary terminals. The resistance should be within the manufacturer's specifications. If the coil is faulty, replace it.
Next, check the ignition wires by inspecting them for damage or corrosion. If the wires are faulty, replace them.
Finally, check the spark plugs by removing them from the engine and inspecting them for wear, fouling, or damage. If the plugs are faulty, replace them.
If you have completed all of these steps and you still do not have spark, the problem may be with the electrical connections. Check all of the connections in the ignition system for looseness, corrosion, or damage. If any of the connections are faulty, repair or replace them.
