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Home >> Oldsmobile >> 1990 >> Custom Cruiser >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Air Injection >> Deceleration Valve
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Deceleration Valve

  1. Remove air cleaner. Remove and plug vacuum hose to air cleaner. Connect tachometer to engine. With engine at idle, remove deceleration valve signal hose from vacuum port.
  2. Reconnect signal hose to deceleration valve while listening for air flow through ventilation pipe into deceleration valve. Engine speed should drop when hose is reconnected.
  3. If airflow lasts less than one second or engine speed does not drop, check for defective hose(s) or deceleration valve.