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Vacuum Amplifier

  1. Check for adequate manifold vacuum. With engine warm and idling, connect vacuum gauge to port "O" on vacuum amplifier, leading to EGR Ported Vacuum Switch (PVS). Vacuum should not read more than 2 in. Hg at idle.
  2. Disconnect venturi hose at carburetor. Increase engine speed to 3000 RPM on 2.3L engines, or 2000 RPM on all other engines. Vacuum should not change. Maintain high engine speed and reconnect carburetor venturi hose.
  3. Vacuum gauge should register at least 4 in. Hg. Return engine to idle. Vacuum gauge should return to initial reading. If vacuum gauge does not return to initial reading, replace vacuum amplifier.
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