1997 Geo Metro BaseFACTORY OEM SERVICE PROCEDURE

Electronic Ignition Timing Control

Ignition timing is calculated by PCM based on current engine status. PCM receives signals indicating vehicle speed, manifold vacuum and engine coolant temperature. PCM selects an appropriate, preprogrammed ignition timing adjustment. A signal is sent from PCM to distributor igniter and changes ignition timing accordingly. For adjusting procedures, see IGNITION TIMING in the ADJUSTMENTS article.

Factory Service Tools

Use the Manual With the Right Hardware

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

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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.