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Purge valve

Lynn Erickson

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This valve is located between the fuel injection servo and the fuel injection distribution block.


In one position it allows fuel coming from the servo to be routed to the distribution block, and out to the individual injectors. (This is the normal position)


In the other position, The injection side of the servo is vented back to the fuel tank, fuel will flow through the pumps, through the servo, and dumped back into the fuel tank. No fuel flows to the distribution block or injectors.


The valve is used during starting and stopping the engine to vent the fuel/vapor back to the fuel tank.





Before cranking the engine, the valve is placed in the Purge position and the fuel pump is turned on. Any pressure that is a result of vaporized fuel (vapor lock) is now vented back into the fuel tank. Cool fuel flows through the servo, up to the valve, and into the fuel tank. The fuel system is now purged and there is no vapor lock.


As you start cranking the engine, move the valve to the Normal position, fuel now flows to the injectors and the engine starts





Move the valve to the Purge position, fuel no longer flows to the injectors, but is vented back to the tank. This eliminates run-on and/or diesieling that sometimes results when shutting down using the Mixture control to shut down the engine. No fuel, no run-on.


Leave the valve in the Purge position after shutdown. This eliminates vapor pressure from pushing fuel through the block/fuel injectors and into the cylinders (hot start)



This valve is standard on the Airflow Performance fuel injection systems.






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