Checking Secondary Ignition & Timing
- 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.
- If secondary ignition pattern is not okay, repair indicated component in secondary ignition system. Perform TEST VER-2 . If secondary ignition pattern is okay, momentarily disconnect and reconnect spark plug wires one at a time from distributor. Observe secondary kilovolt line.
- 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, go to next step.
- Turn ignition off. Remove all spark plugs. Install a compression gauge in each cylinder one at a time. Record compression readings. If all cylinders have at least 100 psi (7 kg/cm2 ) and are within 25 percent of each other, go to next step. If all cylinders do not have at least 100 psi (7 kg/cm2 ) and/or are not within 25 percent of each other, go to next step.
- Install spark plugs and spark plug wires. Start engine. Ensure engine temperature is more than 180°F (82°C) before proceeding. Using scan tool, read total 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, ignition timing is operating properly. Test is complete.