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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 27 (Engine Controls - Tests W/Codes - 3.0L) >> Self-Diagnostic Tests >> Test NTC-2A - Checking Secondary Ignition & Timing

Test NTC-2A - Checking Secondary Ignition & Timing

WARNING: This page is about a different car, the 1995 Plymouth Voyager, 1995 Plymouth Grand Voyager, 1995 Dodge Grand Caravan, and 1995 Dodge Caravan. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn engine off. Connect engine analyzer to engine. Start engine, and let it idle. If engine will not idle, maintain engine speed for reading scope pattern. Set scope to read display or parade pattern. Follow equipment manufacturer's procedure for pattern analysis.
  2. If secondary ignition pattern is not okay, repair indicated component in secondary ignition system. Perform TEST VER-2. If secondary ignition pattern is okay, disconnect any spark plug wire. Observe secondary kilovolt line.
  3. If open circuit secondary voltage is not at least 25 kilovolts, replace electronic ignition coil. Perform TEST VER-2. If open circuit secondary voltage is at least 25 kilovolts, reinstall spark plug wire.
  4. Ensure engine temperature is more than 180°F (82°C) before proceeding. Disconnect Engine Coolant Temperature (ECT) sensor connector. When ECT sensor is disconnected, ECT sensor DTC will set and warning light will come on. Connect a timing light to engine.
  5. Check ignition timing. If ignition timing is not within 2 degrees of specification, adjust ignition timing to specification. Perform TEST VER-2. If ignition timing is within 2 degrees of specification, reconnect ECT sensor.
  6. Using scan tool, read spark advance. Increase engine speed to 2000 RPM. If spark advance does not change with increase in RPM, replace Powertrain Control Module (PCM). Perform TEST VER-2. If spark advance changes with increase in RPM, erase ECT DTC using scan tool. ECT sensor and ignition timing are operating properly. Test is complete.
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