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Throttle Positioner: Tercel

  1. With engine coolant temperature below 122°F (50°C), start engine and increase engine speed to 3500 RPM. Disconnect vacuum hose from throttle positioner diaphragm A. Throttle positioner should now be set.
  2. Warm engine to normal operating temperature. Check and adjust idle speed if required. Disconnect and plug vacuum hoses from EGR valve and throttle positioner diaphragms A and B. Throttle positioner should now be set.
  3. With throttle positioner activated, engine speed should be 1400 RPM. If not, correct by turning throttle positioner adjusting screw making sure cooling fan is off. Reconnect vacuum hose to diaphragm B and see that engine returns to idle within 2-6 seconds.
  4. Reconnect vacuum hose to diaphragm A. Disconnect and plug vacuum hose located between TVSV and VTV 1 at VTV 1 and vacuum hose from diaphragm B. Increase engine speed to above 4500 RPM and plug VTV 1 pipe.
    NOTE: Ensure that stopper lever is separated from throttle positioner adjusting screw before plugging pipe.
  5. Release accelerator. Engine speed should be 2500-3000 RPM. Remove plug from VTV 1 pipe. Engine speed should return to 1400 RPM within 3-10 seconds. Reconnect all hoses.
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