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Home >> Toyota >> 1990 >> Corolla Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Exhaust Gas RECIRCULATION (EGR) Check >> System Test
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System Test

  1. Ensure modulator filter is clean and in good condition prior to performing test. Clean filter with compressed air as required. Disconnect vacuum hose from EGR valve.
  2. Using a "T" connector, connect a vacuum gauge in EGR valve vacuum line. Check that engine starts and runs at idle. This ensures proper seating of EGR valve.
  3. Different vacuum switching valves are used depending on model. The Bi-Metallic Vacuum Switching Valve (BVSV), Vacuum Switching Valve (VSV) and EGR modulator can be checked with engine coolant below minimum temperature and specified engine RPM in accordance with application. See EGR SPECIFICATIONS  table.
  4. Operate engine with engine coolant below minimum temperature and specified RPM. No vacuum reading should be obtained when operated with engine coolant below minimum temperature.
  5. Operate engine at normal operating temperature and specified RPM. See EGR SPECIFICATIONS  table for specified engine RPM. A low vacuum reading should be obtained.
  6. At 5000 RPM, no vacuum should exist. Disconnect hose from the "R" port of EGR vacuum modulator. Using additional hose, connect "R" port directly to intake manifold. High vacuum reading should be obtained at specified engine RPM. See EGR SPECIFICATIONS  table.
    NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
  7. To check EGR valve, apply vacuum directly to EGR valve with engine idling. Engine should run rough. If system did not operate as described, each component should be tested.
EGR SPECIFICATIONS

Model Minimum Temperature RPM
2WD 4A-GE 95°F (35°C) 3500
4WD 4A-FE 95°F (35°C) 2500
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