Turn ignition off. Unplug ignition module 4-pin connector. Disconnect each ignition coil pack 2-pin connector.
Turn ignition switch to ON position. Connect ohmmeter between terminal No. 2 of third ignition coil and ground. Using a 3-volt dry cell battery, apply 3 volts to terminal No. 2 of 4-pin connector. With 3 volts applied, ensure ohmmeter indicates momentary continuity. See Fig 2.
Connect ohmmeter between terminal No. 2 of first ignition coil and ground. Apply 3 volts to terminal No. 4 of 4-pin connector. With 3 volts still applied to terminal No. 4, also apply 3 volts to terminal No. 2. Check that ohmmeter indicates momentary continuity. See Fig 2.
Connect ohmmeter between terminal No. 2 of second ignition coil and ground. Apply 3 volts to terminal No. 3 of 4-pin connector. With 3 volts still applied to No. 3, also apply 3 volts to terminal No. 2. Ensure ohmmeter indicates momentary continuity. See Fig 2.

Fig 1: Ignition System Schematic (Supra Turbo)

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Ignitor Power Transistor Check