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Home >> Honda >> 1985 >> Prelude Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> EGR System >> System Testing >> Cold Engine
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Cold Engine

  1. Disconnect vacuum hose No. 16 from EGR valve and connect vacuum gauge to hose. Start engine and raise engine speed to 4500-5000 RPM. Vacuum should not be available.
  2. If vacuum is not available, proceed to HOT ENGINE  test. If vacuum is available, check for voltage at EGR control solenoid valve A (Yellow/White wire at emission control box connector).
  3. If there is voltage, replace EGR control solenoid valve A and retest. If there is no voltage, check thermosensor operation, wiring, and fuses and retest. Check thermosensor and vacuum switch C.
  4. Check for voltage at control unit connector (Black/Yellow wire) with ignition on. There should be voltage. If no voltage, check wiring. Check Brown/Black wire for continuity between control unit and ground. There should be continuity.
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