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All Models Except Omni and Horizon

  1. Measure and record battery voltage. Battery specific gravity must be at least 1.220 (temperature-corrected) to deliver proper voltage to cranking (ignition) system.
  2. Insert a piece of paper between idle adjusting screw and carburetor sensor, or insure screw does not contact sensor. Connect voltmeter negative lead to ground.
  3. Turn ignition to "RUN" position and measure voltage at carburetor switch terminal. If voltage is approximately 5 volts, proceed to step  7.
  4. If voltage is less than 5 volts, turn ignition to "OFF" and disconnect the 10 pin connector from computer. Turn ignition to "RUN" and measure voltage at pin "2" of 10 pin connector. Voltage should be within 1 volt of battery voltage.
  5. If voltage is correct, proceed to step  7. If voltage is incorrect, check and repair wiring and/or connections between pin "2" and ignition switch.
    NOTE: All tests are made through 10 pin connector unless otherwise noted.
  6. Turn ignition switch "OFF" and check continuity between pin "7" and carburetor switch terminal. If there is no continuity, check wire between pin "7" and carburetor switch. If continuity exists, check continuity between pin "10" and ground. If continuity exists, replace computer. If there is no continuity, check wire from pin "10" to ground.
    NOTE: Proceed with remainder of this test only if engine fails to start.
  7. Turn ignition to "RUN" position and connect positive lead of voltmeter to pin "1". Connect negative lead to ground. Voltage should be within 1 volt of battery voltage, If voltage is correct, proceed to step  10. If voltage is incorrect, proceed as follows.
  8. Turn ignition "OFF". Measure resistance between pins "5" and "9" for run pick-up coil and between pins "3" and "9" for start pick-up coil (dual pick-up distributors) using an ohmmeter. Resistance should be within 150-900 ohms. If resistance is correct, proceed to step  11. If resistance is incorrect, proceed as follows.
  9. Disconnect pick-up coil leads at distributor and measure resistance across pins of distributor connector. Resistance should be 150-900 ohms. If resistance is correct, wires between pins "3", "5", "9" and pick-up coil connector are shorted or broken. If resistance is incorrect, pick-up coil assembly should be replaced.
  10. Connect 1 lead of ohmmeter to ground and other lead to each of the pins of the pick-up coil assembly connector (at distributor). No continuity should exist. If continuity exists, pick-up coil is shorted and should be replaced.
  11. Remove distributor cap, check air gap of pick-up coil(s). If air gap is incorrect, adjust to specifications. Install distributor cap and reconnect all wiring. Start vehicle, if vehicle fails to start, install new computer.
  12. If vehicle now starts, system is functioning properly. If vehicle would not start when new computer was installed, install old computer and repeat test procedures because testing procedure was not performed correctly.
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