2. Checking the ignition spark using the old method, holding the end of the high voltage wire at a short distance from the unit is not recommended by manufacturers, as the insulation of the coil can be damaged.
Engine won't start
3. If the ignition system appears to be faulty, use a multimeter to check the full battery voltage in the high voltage ignition circuit and the distributor ignition integrated circuit on black and white (or black and red) wire If the battery voltage is low, check the circuit from the battery through the ignition socket to the distributor and the high-voltage winding of the coil, and repair any damage found.
4. With the ignition on, check the battery voltage on the blue wire of the integrated ignition unit. If the battery voltage is insufficient, check the primary winding of the coil. Replace the coil if it is faulty.
5. To check the integrated ignition unit, disconnect the distributor ground wire, connect a volt meter between the distributor ground clamp and the negative battery terminal (measure positive voltage drop), disconnect the ignition coil high voltage wire from the distributor cap and ground it, measure the voltage by reading it while turning the engine with the starter for ten seconds.
6. If the result is 0.5 V or less, replace the integrated ignition unit. If the result is more than 0.5 V, check the distributor and engine grounding, as well as the connection of the negative battery terminal to chassis ground.
7. The operation of the integrated ignition unit can be directly checked only by replacing a new component.
8. The above checks will reveal any damage in the low voltage circuit. Check the high voltage circuit as described below.
Misfires
9. Irregular misfires may be due to loose connections or an open in the low voltage circuit of the system, or due to damage to the high voltage circuit on the distributor runner.
10. Check the reliability of the ignition distributor connections.
11. Check that the ignition coil cover, distributor cover and high voltage wires are clean and dry. Measure the resistance of the high voltage wire from the coil to the breaker-distributor cover.
12. Inspect the inside of the breaker-distributor cover and the distributor runner.
13. Regular ignition cut-off may be due to damage in the distributor cap, high voltage wires or spark plugs.
14. If there is no high voltage on any one wire, the damage may be in the wire itself or the breaker-distributor cover. If there is high voltage on all wires, the damage is in the spark plug.
15. If there is no high voltage on any spark plug, check the ignition coil windings. Replace the coil if it is faulty.