On the 1989 Honda Civic, the code 8 and the code 4 are both pointing to a problem with the Crankshaft Position Sensor. On this vehicle, the Crankshaft Sensor is built into and part of the Distributor Assembly. Carefully inspect the Orange wire and the White wire for any loose, broken, damaged or rubbed-through wires. If the visual inspection checks ok, the harness should be tested for any shorts or opens. And the on-board computer tested for functionality. If the testing proves both are good, replace the Distributor Assembly.
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