EFE (Early Fuel Evaporation) Valve Questions

[Goldie Driver]

Hoping someone here can answer 2 questions about the vacuum operated PS side exhaust valve for me.

Is the valve a spring open, vacuum close design ?

Should there be vacuum present to the actuator when the engine is fully warmed?

Trying to diagnose a WOT clatter that has been present since I got Goldie (1980 K15 Suburban, Federal Emissions).

Thanks !

Britt

 

[Goldie Driver]

Well, from a 75 - 82 Chilton's:





So, I think I will leave the vaccuum line disconnected and plugged since I discovered vacuum this morning on the line while the engine was fully warmed up ( after 27 or so miles of driving)

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