1990 Geo Metro XFiFACTORY OEM SERVICE PROCEDURE

Available Spark

  1. Crank engine and check for a strong Blue spark at coil wire and each spark plug wire using Spark Tester (ST-125). If spark tester is not available, use spark plug with ground electrode broken off to create expanded gap, or using insulated pliers. Another check is to hold high-tension wire terminal 5/16" (8 mm) from a ground while cranking engine.
  2. If spark does not occur, check ignition coil, ignitor, rotor and wiring connections. If connections are good, use an ohmmeter to check resistance of high-tension wires. See HIGH TENSION WIRE RESISTANCE table. If resistance is not within specification, replace wires.
  3. Check for voltage at ignition coil positive terminal. If voltage is not present, check wiring between ignition switch, coil and ignitor. If voltage is present, check ignition coil resistance. See IGNITION COIL RESISTANCE table. If ignition coil resistance is incorrect, replace coil.
  4. If ignition coil resistance is correct, check pick-up coil resistance. See PICK-UP COIL RESISTANCE table. If pick-up coil resistance is incorrect, replace pick-up coil or distributor. If resistance is within specification, check air gap between reluctor and pick-up coil. See PICK-UP COIL AIR GAP table.
  5. If air gap is incorrect, adjust as necessary. If air gap is correct, check ignition signal from ECM. See appropriate trouble code chart in TESTS W/CODES article. If signal is okay, replace ignitor.
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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.