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Spark Timing Advance Test

  1. This procedure is applicable to all TFI-IV equipped vehicles. Spark advance is controlled by ECA. This procedure checks capability of ignition module to receive spark timing commands from ECA on the SPOUT circuit. A varying voltage signal is necessary on SPOUT circuit for ECA to transmit data. A KOER Code 18 or Code 213 may be set when SPOUT circuit is open or shorted. For additional information on TFI ignition systems, see THEORY/OPERATION article in the ENGINE PERFORMANCE Section.
  2. Check SPOUT circuit voltage at TFI module. Ensure ignition switch is in OFF position. Disconnect SPOUT in-line connector near TFI module. If connector is SHORTING BAR type, remove SHORTING BAR.
  3. Attach negative (-) voltmeter lead to distributor base and positive (+) lead to TFI module side of the SPOUT connector. Start engine and measure voltage at idle. Measure voltage at ECA side of SPOUT connector.
  4. Voltage readings should be 4-8 volts. If voltage on TFI module side is okay, TFI module is okay. This voltage signal is necessary for TFI module to receive ECA SPOUT signal. If voltage signal from ECA to SPOUT connector is as specified, circuit from ECA to SPOUT connector is okay. If either voltage signal is not as specified, go to next test. If both voltage signals are as specified, check ignition timing advance.
  5. Check SPOUT circuit continuity. Push TFI module connector tab to release connector. Separate wiring harness connector from ignition module. Inspect for dirt, corrosion and damage.
  6. Using a small straight pin inserted into harness connector terminal No. 5, measure resistance between terminal and TFI module side of SPOUT connector. Resistance should be less than 5 ohms. If resistance is 5 ohms or more, repair wiring as necessary.
  7. Measure resistance between ECA side of SPOUT connector and pin No. 36 at ECA connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair wiring between SPOUT connector and ECA.
  8. Check Ignition Timing Advance. With SPOUT connector disconnected, run engine at idle and ensure timing is at base timing adjustment. See ADJUSTMENTS article in the ENGINE PERFORMANCE Section. Stop engine.
  9. Connect SPOUT connector and start engine. Timing should advance from base timing specification. Increase engine RPM and ensure timing advances. If time does not advance, check TFI module. If module is okay, replace ECA.
Fig 1: TFI-IV Ign. System Wiring Diagram (Except Closed Bowl Dist.)
G91I14355Courtesy of FORD MOTOR CO.
Fig 2: TFI-IV Ign System Wiring Diagram (Closed Bowl Distributor)
G91J14356Courtesy of FORD MOTOR CO.
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