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
Temperature Sensor II (EZF Engine Temperature) Test
- Disconnect EZF ignition control unit. Connect ohmmeter between terminal No. 23 and ground. See Figure. Ohmmeter reading should be 4400-6600 ohms at 32°F (0°C), 1400-3600 ohms at 60-85°F (15-30°C), and 1000-1300 ohms at 105°F (40°C).
- Ohmmeter reading should be 250-390 ohms at 175°F (80°C), or 160-210 ohms at 100°F (212°C). If readings are incorrect, test resistance at sensor. DO NOT connect ohmmeter leads on sensor contacts.
- Repeat test on second sensor contact as 2 independent temperature sensors are used. Engine temperature sensor should advance ignition timing when engine is cold and under load.
Factory Service Tools
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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.