1978 Mazda Cosmo Automatic TransFACTORY OEM SERVICE PROCEDURE

1977 Models

  1. Turn ignition on. Unplug connector at anti-afterburn valve solenoid. See Figure. A "clicking" sound should be heard from solenoid when disconnected. If not, replace solenoid.
  2. Connect tachometer to engine. Start and run engine at idle. Disconnect air hose from deceleration control valve at air cleaner. Block air hose opening with hand. Engine speed should not change noticeably.
  3. On manual transmission equipped vehicles, plug hose opening with hand and disconnect coasting valve solenoid wire. Suction should now be felt at air hose opening.
  4. On Federal models, push choke knob fully in. Suction should now be felt at disconnected vacuum tube. On California models, suction should be felt 104-156 seconds after starting engine.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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