1994 Ford Mustang Base, 2D Convertible, AutomaticFACTORY OEM SERVICE PROCEDURE

Spark Check

  1. Check the DI system (formerly Thick Film Ignition-IV (TFI-IV) system) for fault codes and repair if necessary. See QUICK TEST in appropriate TESTS W/CODES article listed below. If no fault codes are retrieved, check ignition system wiring harness connectors for damage, corrosion and tight fit. See Fig 1 .
  2. If no fault codes are retrieved and vehicle starts, problem is intermittent, go to appropriate TESTS W/O CODES article listed below. If no fault codes are retrieved and vehicle is a no-start, connect a high-output spark tester between ignition coil wire and engine ground. Check for spark at coil wire while cranking engine. A consistent Blue spark should be present.
  3. If spark is present, go to step 4). If no spark is present, remove distributor cap and crank engine to ensure distributor rotates. If okay, check resistance of coil secondary wire. Resistance should be less than 7000 ohms per foot. Service coil wire if necessary and retest. If spark is not present, proceed to appropriate I - SYS/COMP TESTS article listed below or the appropriate TESTS W/O CODES article in this section listed above.
  4. On all models, if a consistent Blue spark is present at coil wire during cranking, inspect distributor cap and rotor for cracks or carbon tracking. Service as necessary and test spark output at spark plugs. If spark is present at spark plugs and engine will not start, go to appropriate TESTS W/O CODES article listed in the previous paragraph.
Fig 1: DI System Electrical Diagram (5.0L)
G93I39493Courtesy of FORD MOTOR CO.
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