Preliminary Tests
- A malfunction in the EFC system may result in engine surge, hesitation, rough idle and/or poor fuel economy. Before making any tests, check all vacuum and electrical wiring for proper routing and connections, and check for exhaust and intake manifold leaks.
- Check for spark at spark plug wire, for fuel in carburetor, for fouled spark plugs, and for improper engine timing. Using an ohmmeter, check resistance of ignition coil-to-distributor secondary wire. Resistance should be 250-600 ohms per inch (3000-7200 ohms per foot). Replace wire if not to specifications.
- Connect ohmmeter leads to ignition coil positive and negative terminals. Coil primary resistance should be 1.6-1.8 ohms. Remove coil secondary wire and connect ohmmeter leads to the coil negative and secondary terminals. Coil secondary resistance should be 9400-22,700 ohms. If either ohmmeter reading is not to specification, replace ignition coil.
- If tests in steps 2) and 3) prove satisfactory, system testing may begin.
NOTE:
The Spark Control Computer controls ignition timing as well as air/fuel mixture. Before testing EFC system, perform SPARK CONTROL TEST.