VENTURI Vacuum Amplifier
NOTE:
Amplifiers have built-in calibrations, and no external adjustments are required. If amplifier bias test reveals malfunction, replace amplifier. Always check venturi vacuum amplifier last, after checking all other basic EGR components.
- With engine at normal operating temperature, curb idle set and adequate manifold vacuum supplied to system, connect vacuum gauge to hose at amplifier port "O". See Fig 1 . Gauge may read as much as 2 in. Hg at idle.
- Disconnect venturi hose (amplifier port "V") at carburetor and increase engine speed to 2000-3000 RPM. Vacuum should not change.
- While maintaining high engine speed, connect venturi hose. Vacuum should increase to 4 in. Hg. Return to idle. Gauge should return to initial reading. If amplifier does not perform as specified, replace amplifier.