Ignition System

Turn ignition on. Connect negative lead of voltmeter to ground and positive lead to negative terminal of ignition coil. Voltage should be within 1 volt of battery voltage. If not, proceed to step 8).
If reading is step 1) was within 1 volt of battery voltage, turn ignition off and disconnect 2-pole connector. See Fig 1.

Fig 1: Ignition System Tests at 2-Pole Connector
Courtesy of SUBARU OF AMERICA, INC.
Using an ohmmeter set to the x100 scale, measure resistance between terminals in distributor side of 2-pole connector. Reading should be 600-850 ohms. If not, replace pick-up coil.
If reading was within specifications, turn ignition off. Using an ohmmeter set to the x1 scale, measure resistance between ground and ignition control unit side. Resistance should be less than 0.5 ohm. If not, check ground wire at regulator mounting screw.
If resistance is less than 0.5 ohm, turn ignition off and check air gap between reluctor and pick-up coil. Adjust as necessary.
If air gap was originally within specifications, turn ignition off and disconnect 2-pole connector. Disconnect secondary wire from distributor and hold wire 1/4" from engine ground. Turn ignition on and check whether spark jumps when a small voltage (1-6 volts) is intermittently applied to terminals 1 and 2 on ignition control unit side of connector.
NOTE: Do not use battery voltage for this test or damage may occur to ignition control unit.
If spark occurs, there is no trouble with electronic ignition system. If no spark occurs, replace ignition control unit.
If reading in step 1) was not within 1.0 volt of battery voltage, turn ignition on and check voltage at positive terminal of ignition coil. If not equal to battery voltage, check wiring between ignition switch and positive terminal of ignition coil. Repair or replace as necessary. If okay, check connector, switch, fuse and wiring back to the battery.
If reading at coil positive terminal was within 1.0 volt of battery voltage, disconnect lead at negative terminal (coming from ignition control unit) and turn ignition on. Voltage at negative terminal should be within 1.0 volt of battery voltage.
If it is, but engine will not start, replace ignition control unit. If not within 1.0 volt, remove tachometer lead (if equipped) at ignition coil. Turn ignition on and again check voltage at negative terminal of coil. If reading is correct, but engine will not start, check wiring harnesses from negative terminal of coil to tachometer for short circuit. If still not within 1.0 volt, replace ignition control unit.