Ignition Control Module: Testing and Inspection

The ESC igniter is used on fuel injected turbocharged models only.
1. Start engine and allow to reach normal operating temperature.
2. Connect a suitable timing light and tachometer to engine as per manufacturer's instructions.
3. Check ignition timing. If timing is incorrect, adjust to specifications. If timing is correct, check distributor (centrifugal or vacuum) advance operation. If distributor advance is operating properly, set engine speed to 1,000 RPM.
4. Gently tap injection mixer mounting stud (left front) using a suitable mallet. After tapping stud, ignition timing should be retarded. If timing is retarded, measure voltage between terminal 7 and ground of ESC igniter. If indicated voltage measures 1 volt or less, pressure sensor is defective or a short in wire harness is indicated. If voltage exceeds 1 volt, ESC igniter is defective.
5. If after tapping mixer mounting stud timing is not retarded, disconnect electrical connector from pressure sensor to retard timing. If timing is retarded, check shielding wire of detonation sensor signal circuit for continuity. If continuity is indicated, detonation sensor or ESC igniter is defective. If no continuity exists, a short in wire harness is indicated. If timing is not retarded, gently tap mixer mounting stud (left front). If timing is still not retarded, ESC igniteror detonation sensor is defective. If timing is retarded, disconnect detonation sensor electrical connector. An 8° retard should be obtained; if not, ESC igniter is defective. If 8° retard is obtained, ESC igniter is satisfactory.
6. Reduce engine speed to idle, then stop engine.
7. Connect pressure sensor and detonation sensor electrical connectors.