1985 Porsche 928 AutomaticFACTORY OEM SERVICE PROCEDURE

Load Sensor Test

  1. Connect timing light to engine. Start engine and increase speed to 4000 RPM. Ignition timing should be 37-43 degrees BTDC. If setting cannot be reached, apply vacuum to ignition control unit until it does.
  2. Disconnect vacuum hose from EZF ignition control unit. Ignition timing should change to 17-23 degrees BTDC. If timing does not change, replace ignition control unit. If timing changes, check vacuum hose or intake manifold for leaks.
Chapter Navigation
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

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.