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EGR Vacuum Modulator

  1. Disconnect vacuum hoses from EGR vacuum modulator. Block ports "P" and "R" of EGR vacuum modulator. See Figure.
    NOTE: Ports "P" and "R" are the double ports on side of EGR vacuum modulator. Port "Q" is the single port on side of EGR vacuum modulator.
  2. Apply air pressure to port "Q". See Figure. Air should pass freely through air filter side of EGR vacuum modulator.
  3. Start and operate engine at specified RPM. See EGR VACUUM MODULATOR TESTING SPECIFICATIONS  table. Repeat test procedures in steps 1) and 2). Strong resistance of airflow should be felt. Replace EGR vacuum modulator if resistance is not felt. Reconnect vacuum hoses to proper locations.
EGR VACUUM MODULATOR TESTING SPECIFICATIONS

Application Engine RPM
Tercel 2500
NOTE: Bimetallic Vacuum Switching Valve (BVSV) may be referred to as a Thermal Vacuum Valve (TVV). When testing BVSV, use proper illustration to determine component location. See Figure-24.
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