Connect the voltmeter to the battery terminals.
Turn on the ignition, the voltage should be about 12 V. Otherwise, the battery is discharged.
Pull out the wire from terminal 4 (central) from the middle of the distributor cap and place it against the ground. Turn off the starter and measure the voltage. The control value is about; 10 V.
Transistor ignition system with additional resistance
Check the input voltage on the additional resistor. To do this, connect the voltmeter to the black/red wire on the additional resistor of 0.4 Ohm and to ground. The control value is 12 V. Then turn on the starter, the voltage should reach 8.5 V.
Connect the voltmeter to terminal 15 of the ignition coil and to ground. The control value is 4.5 V.
Connect the voltmeter to terminal 1 of the ignition coil and to ground. The control value is from 0.5 to 2 V. If the measured value is greater, then the switch is defective;. If the control value is reached, but there is no ignition spark, then you need to check the sensor in the distributor or the secondary winding of the ignition coil. Check the additional resistance with an ohmmeter. To do this, disconnect the corresponding wire from the resistance and connect the measuring device to the resistance contacts. Control values: approximately 0.4
Note: The values are valid for a temperature of about 20°, as the temperature increases the resistance increases.
Check the resistance of the ignition coil.
The resistance of the primary winding, measured between terminals 15 and 1, should have a value of 0.33 to 0.46 ohms. The resistance of the secondary winding, measured between terminals 1 and 4, should have a value of 7 to 12 kohms.
Check the closed state angle.
As already stated, the closed state angle adjustment is not possible. The check is only used to check the operation of the switch. If the control value is not reached when measuring the closed state angle, then the next thing to check is the ignition distributor sensor. If it is working properly, then the switch must be replaced.
Checking the ignition distributor sensor. Disconnect the ignition distributor control wire from the switch, connect an ohmmeter between terminal 7 and 31d and check the sensor resistance. The value should be 600±100 Ohm. When the engine is cold, the resistance value should be in the lower half of the range of acceptable values, and when the engine is warm, in the upper half of the range of acceptable values.
Check the sensor coil for short circuit with ground. To do this, connect an ohmmeter to terminal 7 and ground. The ohmmeter should show infinity. Additionally, check the sensor for mechanical damage. There should be an air gap between the rotor and the stator. If the sensor is defective, you will have to replace the ignition distributor completely.