Inspection Procedure
INSPECTION PROCEDURE FOR DTC 141. CHECK FOR SPARK.
- Disconnect the high tension cord from the Distributor, hold its end about 12.5 mm (1/2") from the ground, see if spark occurs while the engine is being cranked.
^ If OK proceed to step 2.
^ If not OK proceed to step 4.
Hint; To prevent excess fuel being injected from the injectors during this check. Don't crank the engine for more than 1 - 2 seconds at a time.
2. CHECK FOR OPEN AND SHORT IN HARNESS AND CONNECTOR IN IGF SIGNAL CIRCUIT BETWEEN ENGINE CONTROL MODULE AND IGNITER.
^ If OK proceed to step 3.
^ If not OK repair or replace harness or connector.
3. DISCONNECT IGNITER CONNECTOR AND CHECK VOLTAGE BETWEEN TERMINAL IGF OF ENGINE CONTROL MODULE CONNECTOR AND BODY GROUND.
- Disconnect igniter connector.
- Connect the Check Harness A.
- Turn ignition switch ON.
- Measure voltage between terminal IGF of ECM connector and body ground.
OK if: 4.5 - 5.5 volts
^ If OK replace igniter.
^ If not OK check and replace ECM.
4. CHECK VOLTAGE BETWEEN TERMINAL IGT OF ECM CONNECTOR AND BODY GROUND.
- Connect the Check Harness A.
- Measure voltage between terminal IGT of ECM connector and body ground when engine is cranked.
OK if:.... 0.5 - 1.0 volts
(Neither 0.0 volts nor 5.0 volts)
^ If OK proceed to step 5.
^ If not OK proceed to step 8.
5. CHECK VOLTAGE BETWEEN TERMINAL 3 OF IGNITER CONNECTOR AND BODY GROUND.
- Disconnect igniter connector.
- Measure voltage between terminal 3 of igniter connector and body ground, when ignition switch is turned to "ON" and "STA" position.
OK if:.... 9.0 - 14.0 volts
^ If OK proceed to step 6.
^ If not OK check and repair igniter power source circuit.
6. CHECK FOR OPEN AND SHORT IN HARNESS AND CONNECTOR BETWEEN IGNITION SWITCH AND IGNITION COIL AND IGNITER.
^ If OK proceed to step 7.
^ If not OK repair or replace harness or connector.
7. CHECK IGNITION COIL.
- Disconnect ignition coil connector.
- Check primary coil. Measure resistance between terminals of ignition coil connector.
- Check secondary coil. Measure resistance between terminal (+) of ignition coil connector and high tension terminal.
Cold: (from -10°C (14°F) to 50°C (122°F)
Primary coil = 0.21 - 0.33 Ohms
Secondary coil = 6.4 - 11.1 K-Ohms
Hot: (from 50°C (122° F) to 100°C (212°F)
Primary coil = 0.27 - 0.39 Ohms
Secondary coil = 8.2 - 13.0 K-Ohms
^ If OK replace igniter.
^ If not OK replace ignition coil.
8. DISCONNECT IGNITER CONNECTOR AND CHECK VOLTAGE BETWEEN TERMINAL IGT OF ECM CONNECTOR AND BODY GROUND.
- Disconnect igniter connector.
- Measure voltage between terminal IGT of ECM connector and body ground when engine is cranked.
OK if:.... 0.5 - 1.0 volts
(neither 0.0 nor 5.0 volts)
^ If OK replace igniter.
^ If not OK proceed to step 9.
9. CHECK FOR OPEN AND SHORT IN HARNESS AND CONNECTOR IN IGT SIGNAL CIRCUIT BETWEEN ECM AND IGNITER.
^ If OK check and replace ECM.
^ If not OK repair or replace harness or connector.
INSPECTION USING AN OSCILLOSCOPE
