1987 Porsche 928 AutomaticFACTORY OEM SERVICE PROCEDURE

Ignition Distributors

Each of the ignition coils are connected with a separate 4-cylinder distributor. The distributors are driven by each respective exhaust camshaft. The distributor driven by exhaust camshaft for cylinders No. 1-4 delivers spark for cylinders No. 1, 4, 6 and 7. The other distributor delivers spark for cylinders No. 2, 3, 5 and 8.

When working with a workshop oscilloscope only 4-cylinders will appear on the screen. The workshop tester must be set to 4-cylinders when checking engine speed.

The double distributor is necessary, since this ignition system works with considerably higher current in the high voltage range. To prevent high voltage from jumping over to the wrong cylinder in the distributor cap, a certain electrode gap is required in the distributor cap.

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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.