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Datsun 280ZX & 810 Models (Calif. Only)

  1. Start engine and warm to normal operating temperature. Accelerate and run engine at 2000 RPM for 5 minutes to stabilize operating condition.
  2. Accelerate engine 2-3 times and allow to idle. Turn idle speed adjusting screw to obtain 700 RPM. Check ignition timing and adjust if necessary. Raise engine speed to 2000 RPM and observe inspection light on bottom of EFI control unit.
  3. Light should blink more than 5 times in 10 seconds, indicating mixture is correct and is being controlled by the computer. If light is blinking properly, system is functioning and no adjustment is required.
  4. If not, turn ignition switch off, disconnect negative battery cable and 35 pin connector from control unit. Disconnect exhaust gas sensor harness connector. Ground sensor terminal of connector.
  5. Check for continuity between terminal No. 31 of control unit connector and chassis ground. If circuit is open, repair or replace EFI harness and repeat test procedure. If continuity exists, reconnect control unit harness and battery negative cable.
  6. Start engine, run at 2000 RPM and observe inspection light on control unit. With exhaust sensor terminal grounded, light should glow. Remove ground wire from sensor terminal and light should go out. If not okay, replace control unit and repeat all test procedures. If okay, proceed to next step.
  7. Turn ignition switch off, disconnect throttle valve switch harness connector and connect a jumper wire between harness connector terminals No. 24 and No. 30. Position harness connector at least 4" away from any secondary ignition wires.
  8. Disconnect and plug distributor vacuum hose. Disconnect air induction hose and canister purge hose at intake manifold. Plug air induction pipe and purge hose fitting on intake manifold. Start engine, accelerate 2-3 times and allow to idle.
  9. Insert CO meter probe into tail pipe (a minimum of 16") and measure CO level. Idle CO level should be less than 5%. If CO level is okay and engine runs smoothly, replace exhaust gas sensor and repeat all test procedures. If CO level is incorrect or if CO level is correct, but engine does not run smoothly, proceed to next step.
  10. Turn ignition switch off and remove air flow meter. Drill a small hole in steel plug covering air by-pass screw. Install a self-tapping screw into hole and remove plug. Reinstall air flow meter, start engine and run to normal operating temperature.
  11. With engine idling, adjust air by-pass screw to obtain a 0.2-1.8% reading on CO meter. If mixture will not adjust, repair or replace air flow meter or other defective EFI components and repeat all test procedures.
  12. If mixture adjusts correctly, replace steel plug in air flow meter and reconnect all hoses and harness connectors. Repeat all test procedures.
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