Troubleshooting

Fig. 4 Breakerless ignition system wiring circuit.:

Prior to testing ignition system, ensure that engine and related systems are operating properly, and note the following and ensure that battery is fully charged. Battery voltage below specifications will cause inaccurate test results. Check wiring harness and connections, Fig. 4, for proper routing, loose connection, or frayed insulation, and correct as needed. Hall transmitter and rotor cannot be replaced separately. If either component is found to be defective, distributor must be replaced as an assembly.

1. Disconnect coil high tension lead at distributor and check length of spark between lead and engine block while cranking engine.
2. If spark is at least 1/2 inch long, proceed to step 3. If not, proceed to step 8.
3. Check the ignition timing. If the timing is correct, proceed to step 4. If it is not, adjust the timing.
4. Check to see that the engine is receiving enough fuel. If it is, proceed to step 5. If it is not, repair the fuel system.
5. Remove the ECU which should be rotated around the ground bolt so the fuse is visible from the side. Pull back the rubber cover on the fuse, and measure the voltage between terminals 2 and 4 of the ECU. Battery voltage should be obtained. If it is, proceed to step 6. If it is not, check the wiring from the ignition switch to the control unit and correct and problems found.
6. Check the ignition coil. The resistance between terminals 1 and 15 should be approximately 1/2 to 3/4 Ohms. The resistance between terminal 1 and the center tower should be approximately 2,400 to 3,500 Ohms. If the resistance readings are correct, proceed to step 7. If they are not, replace the ignition coil.
7. Remove the wire from the distributor. Measure the voltage between terminals 1 and 15 on the ignition coil. The meter should read approximately 6 volts. With the voltmeter still connected, turn on the ignition. Within 1 to 2 seconds the voltmeter reading should drop to 0 volts. If the readings are correct, the engine should now start. If the readings are incorrect, then replace the control unit.
8. Check the secondary circuit of the ignition system. If all components are in good condition then check for a spark capable of jumping 1/2 inch. Proceed to step 9.
9. Detach the control unit, pull back on the rubber cover for the fuse, and check the voltage between terminals 2 and 4. Battery voltage should be obtained. If it is, proceed to step 10. If it is not, check the wiring from the ignition switch to the control unit and correct any problems found.
10. Disconnect the wire from the distributor and measure the voltage between the + and - connections. If battery voltage is obtained, proceed to step 11. If it is not, check the wiring between the control unit and the distributor. If the wiring is sound, replace the control unit.
11. Connect a voltmeter between terminals 3 and 6 of the control unit. Remove the distributor cap and dust cover. Turn the engine so the aperture of the slotted rotor is in the gap of the Hall effect switch. If the voltage reading is 0.4 volts or less, proceed to step 12. If the reading is more than 0.4 volts, replace the distributor.
12. With the meter still connected as above, turn the engine until the slotted rotor blocks the gap between the Hall effect switch. The voltage reading should now be 1.0 volts or more. If the correct voltage is read, return to step 6. If the correct voltage is not obtained, replace the distributor.