LN7 L4-98 1.6L SOHC VIN 4 2-bbl HP (1983)
Power Valve: Description and Operation
The air/fuel ratio must be increased during periods of heavy acceleration or high speed operation. The power enrichment system, controlled by intake
manifold vacuum, supplies extra fuel during these operating conditions. Manifold vacuum is applied to the power valve diaphragm from an opening in
the carburetor base where it is connected by passages in the main body to the diaphragm. During idle and light load conditions, high manifold vacuum
overcomes the force of the power valve spring and the valve is held closed. When the throttle opening is increased and intake manifold vacuum drops,
the valve opens and fuel flows from the bowl through the power valve into the primary main well. This extra fuel is then added to the main metering
system fuel to provide the increased air/fuel ratio necessary for high speed or heavy load operation.
