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
Throttle Switch (Full Load)
- Pull off both EZF and LH control unit plugs. Connect ohmmeter between terminal 12 and ground on disconnected LH control unit plug. In idle position reading should be infinite ohms. At about 2/3 throttle opening, reading should be 0 ohms.
- Full load contact switches in full throttle enrichment and turns off oxygen sensor. If circuit is open, engine will be too lean with poor power output. If circuit is grounded, engine will run rich with high fuel consumption.
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.