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". 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.