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
Fuel Injectors
- If poor power output is reported (too low at full engine load), cross section size of injector pintle could be restricted by carbon. For this test the ring line is lifted and the fuel injectors held in measuring glasses with help of a new injector installed for comparison.
- Remove LH control unit plug. Remove plug "W" on CEB. Apply ground to terminal "W12" and 12 volts of battery voltage to terminal "W13". Bridge terminals 30 and 87 on fuel pump relay "XX". Difference between all fuel injectors must not exceed 10% by volume. If difference is exceeded, replace injectors.
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.