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Spark Check

  1. Using a high output spark tester, check for spark at coil wire while cranking engine. If spark is present, go to step 2). If spark is not present, remove distributor cap and crank engine to check for distributor rotation. If okay, check coil secondary wire resistance. Resistance should be no greater than 7000 ohms per foot.
  2. Place transmission in Neutral. Disconnect TFI wiring harness connector. Attach TFI Ignition Tester (105-000003). Connect Red lead of tester to 12 volts. Attach remote starter to "S" terminal of starter relay. Crank engine with remote starter while observing 2 LED lights on tester. If the PIP light blinks, go to step 4). If not, remove distributor.
  3. Remove TFI module from distributor. Using an ohmmeter, ensure all circuit resistance values are correct. See Fig 1. Refer to the TFI MODULE CIRCUIT RESISTANCE SPECIFICATIONS  table. If readings are incorrect, replace TFI module. If readings are correct, check stator for open winding or short to ground. See appropriate COMPONENT article in the ENGINE PERFORMANCE section.
    Fig 1: TFI Ignition Module Connector Terminal Identification
    G106319Courtesy of FORD MOTOR CO.
    TFI MODULE CIRCUIT RESISTANCE SPECIFICATIONS

    TFI Terminals (1) Ohms
    Ground Pin - PIP More than 500
    Power Pin - PIP Input Pin Less than 2000
    Power Pin - TFI Power Less than 200
    Ground Pin - Ignition Ground Less than 2
    PIP Input Pin - PIP Less than 200
    (1) See Fig 1 for terminal identification.
  4. If TACH light did not blink in step 2), replace TFI module and repeat step 1). If spark is still not present, replace ignition coil and module connector. If the TACH light did blink in step 2), substitute ignition coil with a known working unit and repeat step 1). If spark is now present, verify coil secondary wire resistance is no greater than 7000 ohms per foot and replace ignition coil.
  5. If spark was not present in step 4), connect original vehicle coil and spark tester. Remove pin-in-line connector located near distributor. Crank engine while checking for spark. If spark is present, inspect PIP and ignition ground circuits to verify continuity. See Fig 2 and Fig 3. Repair as necessary.
    Fig 2: TFI System Schematic (W/O Computer Controlled Dwell)
    G90I09245Courtesy of FORD MOTOR CO.
    Fig 3: TFI System Schematic (W/Computer Controlled Dwell)
    G90A09246Courtesy of FORD MOTOR CO.
  6. If spark was not present in step 5), measure battery voltage with negative lead from volt meter attached to base of distributor. Measure voltage at ignition coil positive (+) terminal. Ignition coil positive (+) terminal voltage should be at least 90 percent of battery voltage. If not, check circuitry between ignition coil and ignition switch for wear or damage. Repair as necessary.
  7. If ignition coil positive (+) terminal voltage was at least 90 percent of battery voltage in step 6), remove connector from ignition module. Disconnect starter relay "S" terminal. Turn ignition on. Measure voltage at ignition module connector power terminals No. 3 and 4. See Fig 4. See TFI MODULE VOLTAGE TEST TERMINALS. Voltage should be at least 90 percent of battery voltage.
  8. If not, check circuitry between ignition coil and ignition switch for wear or damage. Repair as necessary. If voltage was at least 90 percent of battery voltage in step 7), inspect wiring between ignition module terminal No. 2 and coil. If okay, check all related circuitry. Replace or repair as necessary.
Fig 4: TFI Ignition Module Connector Terminal Identification
G106319Courtesy of FORD MOTOR CO.
TFI MODULE VOLTAGE TEST TERMINALS (1)

TFI Terminal Ignition Switch Position
With CCD (No. 3) Run & Start
Without CCD
No. 3 Run & Start
No. 4 Start
(1) Computer Controlled Dwell.