81 4X4

Why does the vacuum advance have two vacuum lines? When switching carbs, I've seen guys just use one, and plug other one, and then I've seen guys use both with a "T" into one line. What's the best way to do it? Thanks, Dean

xxxtreme22r

I think this was covered on here before, someone correct me if I am wrong please. The line furthest from the motor is controlled by a vsv which i believe supplies vacuum to the distributor when the motor is cold and retards the timing. The other line is the regular vacuum advance and comes off of manifold/carb vacuum. The ones you see that have removed the one line most likely have a Weber carb. The ones with the tee is defeating the vacuum advance and I would be surprised it even runs right that way.

kdo58

if you have a weber plug the inside one, and use the outside one for your carb.

xxxtreme22r

the one closest to the motor? So I have the description in previous thread backwards?

Gov't Mule

Yeah....closest to motor (inner) goes to the carb....outer gets plugged.

xxxtreme22r

wow ok got to swtich things around on mine. updated previous thread of mine, reflecting the correct alignment.