Remove the protective cap of the ignition distributor and disconnect the spark plug tips.
Caution: When doing this, grasp the tip, not the wire.
Measure the resistance between the individual contacts in the ignition distributor cap and the contacts of the corresponding spark plug tips. Set value: 6±1.2 kΩ.
If there is a deviation from the specified value, unscrew the spark plug tip from the ignition wire. The resistance of the spark plug tip should be 1 kOhm. If it's not. replace spark plug; otherwise, replace the ignition wire or the ignition distributor cap.
With increased resistance, clean the wire connection contacts and repeat the test. If necessary, replace the wire.
By bending the ignition wires near the spark plug tips at a large angle, check for cracking. If required, replace all ignition wires at once.
Check the ignition distributor.
Connect ground wire to battery.
Checking the ignition distributor slider
Under normal sparking resistance (measured in ohms) should not be elevated.
Shine the ignition distributor cap.
Connect an ohmmeter to the ignition distributor slider. Set resistance value approx. 1kΩ +300/-100Ω.