Failure To Start Test
- Measure and record battery voltage. Check battery specific gravity, which must be 1.220 (temperature corrected) to deliver proper voltage to ignition system.
- Remove coil secondary wire from distributor cap and hold 1/4" from a good ground. Prepare a special jumper wire assembly as shown in Fig 1 . With ignition switch on, momentarily touch special jumper wire to ground and coil negative terminal. A spark should be obtained at secondary wire.
- If spark was obtained, proceed to step 6). If no spark resulted, turn ignition off and disconnect 10-wire harness connector from computer. See Fig 2 . Turn ignition back on and again, using special jumper wire, connect negative terminal momentarily to ground. Spark should be obtained.
- If spark was obtained, but engine will not start, computer output is shorted. Replace computer. If no spark resulted in step 3), connect positive lead of voltmeter to coil positive terminal and negative lead to a good ground. Reading should be within 1 volt of battery voltage. If not, check wiring between battery and coil positive terminal.
- If correct voltage was recorded in step 4), measure voltage between ground and coil negative terminal. Again, it should be within 1 volt of battery voltage. Replace ignition coil if there is either no voltage present, or if voltage is present but no spark results when shorting negative coil terminal.
- If no spark was obtained in step 2) or if in step 5) voltage was obtained but engine would not start, hold carburetor switch open with a thin cardboard insulator. Measure voltage between carburetor switch and ground. Reading should be at least 5 volts. If so, proceed to step 10).
- If voltage was not at least 5 volts in step 6), turn ignition off and disconnect 10-wire harness connector from computer. Turn ignition on. Connect positive lead of voltmeter to cavity 2 of connector and negative lead to ground. Reading should be within 1 volt of battery voltage.
- If no battery voltage is present, check wire from battery to ignition switch to cavity 2. Use an ohmmeter if necessary to check continuity of wires. Correct problem and repeat step 7). If voltage was present in step 7), turn ignition off and connect ohmmeter leads to carburetor switch terminal and cavity 7 of 10-wire connector.
- If no continuity is found, check for open wire between cavity 7 and carburetor switch. If continuity was indicated, connect ohmmeter leads to cavity 10 and to a good ground. If continuity exists, replace computer, as correct power is entering computer, but not leaving it. Repeat step 6). If no continuity existed between cavity 10 and ground, check for an open wire in the ground system.
- Reconnect 10-wire harness connector to computer. Turn ignition on and hold secondary coil wire 1/4" from a good ground. Disconnect 3-wire distributor connector from distributor. Attach jumper wire between cavities 2 and 3 of harness connector. A good spark should jump from coil wire to ground.
- If spark resulted, but engine will not start, replace Hall Effect Pick-Up. Before replacing, however, always be sure rotor shutterblades are grounded. Connect 1 ohmmeter lead to a good ground and touch other lead to shutter blade. See Figure . If no continuity, push down on rotor to seat against shaft. If still no continuity, replace rotor. If shutterblade is grounded, then proceed to replace Hall Effect Pick-Up.
- If no spark resulted in step 10), connect voltmeter positive lead to distributor harness connector cavity 1 and negative lead to ground. Reading should be within 1 volt of battery voltage. If no battery voltage is present, proceed to step 15). If voltage was correct, turn ignition off and disconnect 10-wire harness connector from computer.
- Connect ohmmeter leads between cavity 2 (Black/Light Blue wires) of distributor harness connector and cavity 9 of 10-wire connector. Then connect leads to cavity 3 (Gray wire) of distributor harness connector and cavity 5 of 10-wire connector.
- If no continuity is present, repair open wires. If continuity exists, replace computer (power going into computer, but not coming out). Repeat step 10).
- If there was no battery voltage in step 12), turn ignition off, disconnect 10-wire connector and connect ohmmeter leads to cavity 1 of distributor harness and cavity 3 of 10-wire connector. If no continuity exists, repair wire and repeat step 10).
- If continuity existed in step 15), turn ignition on and check for battery voltage with voltmeter positive lead in cavity 2 of 10-wire connector and negative lead in cavity 10. If battery voltage is present, but vehicle will not start, replace computer and repeat step 10). If no battery voltage is present, check ground wire and repeat step 10).