Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1985 Porsche 928 AutomaticFACTORY OEM SERVICE PROCEDURE
Test Equipment
Use the following test equipment to test ignition system. Always refer to manufacturer's instructions for correct test connections.
- DIGITAL MULTIMETER: Volt/Ohm Meter.
- OSCILLOSCOPE (SUN 1010/1080): Use single test leads of inductive clip terminal No. 4 (Blue and Black). Blue and Black terminals are connected on sensor. Set oscilloscope on "Primary +, 4H, 2-Cyl., and 50V. On SUN 1080, the coil test button should be pressed during tests. Set right regulator located underneath oscilloscope adjusting cover to 25V.
- TEST LEADS: In order to avoid damaging EZF ignition control unit, manufacture 2 test leads, 40" (100 cm) long, fitted with 2 flat male connectors (Part No. N174572 ). See Fig 1. Also manufacture one test lead, fitted with 4 connectors (Part No. N0174831 ) soldered to 2 wires about 4" (10 cm) long.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.