Spark Check

1991 Mercury Tracer Base, 4D Sedan, AutomaticSECTION Spark Check
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 1994 Mercury Topaz, 1994 Mercury Sable, 1994 Mercury Cougar, 1994 Lincoln Continental, and 1994 Ford Thunderbird. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check the EI (high data rate) system (formerly Electronic Distributorless Ignition System - EDIS) for fault codes and repair if necessary. See QUICK TEST in appropriate article listed below. If no fault codes are present, check ignition system wiring harness connectors for corrosion and tight fit. See Fig 1, Fig 2, Fig 3 or Fig 4. Clean or repair connectors as necessary.
  2. If wiring and connectors are okay, use Neon Bulb Spark Tester (D89P-6666-A) to check for spark at each spark plug wire while cranking engine. If spark is strong and consistent at each spark plug (one spark per crankshaft revolution), ignition system is okay. If spark is not present, go to IGNITION SYSTEMS in appropriate SYSTEM/COMPONENT TESTS article listed below.
Fig 1: EI Sys. (High Data Rate) Elec. Diag. (3.8L Calif. & 3.0L Flex. Fuel)
G93C39489Courtesy of FORD MOTOR CO.
RENDER: 1.0x

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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.