Vacuum Amplifier
- Check for adequate manifold vacuum. Warm engine and operate at curb idle. Connect vacuum gauge to vacuum amplifier port leading to EGR 3-way solenoid. Vacuum should not be greater than 1.6-2.4 in. Hg at idle.
- Disconnect venturi hose at carburetor. Increase engine speed to 3500 RPM. Vacuum should not change. Maintain high engine speed and reconnect carburetor venturi hose.
- Vacuum gauge should read 3.2-3.8 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.