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 StandardFACTORY OEM SERVICE PROCEDURE
Throttle Switch Full Load
- Pull off both EZF and LH control unit plugs. Connect ohmmeter on terminal 17 of disconnected EZF control unit plug and ground. With throttle switch in idle position, resistance reading should be infinity. With throttle at about 2/3 travel, reading should be 0 ohms (maximum of 10).
- If values are not reached, repeat test directly on switch. Full load contact retards ignition timing by approximately 20°. Test values are with adapter-to-throttle switch plug disconnected at 4000 RPM. See Fig 1 . Timing should be approximately 40° BTDC. With full load contact on plug bridged at 4000 RPM, timing should be approximately 20° BTDC.
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.