I think what you are talking about is the thermotime valve...at least that is what I have on my 78. Basically, it is a time controlled valve that prevents vacuum from going to the WUR when you first start the car.This allows the car to run a little rich during the start up phase. Once the heating element gets hot enough it opens the valve and allows the WUR to lean out the mixture at idle or high vacuum conditions. When you open the throttle that vacuum line now serves to enrichen the mixture.
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Peace, Ron
www.ronorlando.net
78SC Targa 3.2 SS, 964 cams, CIS, SSI's,Dansk
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