Vacuum Amplifier: Testing and Inspection
Conditions
^ Normally warm engine.
^ Proper Curb Idle.
^ Adequate Manifold Vacuum.
Test
^ Connect a vacuum gauge to the hose at the EGR Port O. The gauge may read as much as 6.8 kPa(2 in-Hg) at idle.
^ Disconnect the venturi hose at the carburetor, and increase engine speed to 2000 rpm. Vacuum should not change.
^ Maintain high engine speed, and connect venturi hose. Gauge should register at least 13.5 kPa (4 in-Hg).
^ Return to idle. Gauge should return to initial reading.
^ If the above conditions are not met, replace the VVA.