Quick dizzy vac advance diaphragm connection qu

[keith2.2]

Just been inspecting a few things under the bonnet and noticed that the vac advance diaphragm has a small pipe that goes to free-air.

Is it supposed to be free air? Or should it either be blocked or connected to something?

Thanks!

[zed4]

Should be connected to the plenum

[A900ss]

The advance should be connected from the dizzy to the plenum as devised above but there is also a retard on the other side. It sometimes has a cover, it sometimes doesn't. Either way, no worries about that not being connected.

I've just replaced my advance unit, the retard has no cover. The new unit has made a huge difference to my cruising MPG.

Good luck.

[keith2.2]

Thanks both - I think it's the retard side (nearest the dizzy) - the outer facing connection does indeed go to the manifold.