bmwe21.net forums

What diameter do I need for connecting up the Weber? Mine are all cracked but not near the car atm to measure.

Also - I have a line coming from the weber and one from the intake manifold which go into a t-piece - from there they're connected to the advance side of the vaccuum unit on the dizzy. The (what I assume is) the retard on the back of the vaccuum unit isn't connect to anything - is this right?

Hi,

All the vacuum ports on my 316 are 4mm, so 3mm internal diameter tubing works well, I used this for my weber on as well.

The advance lines sound correct from what I recall. Can't remember where I had the vacuum retard line going on mine, think there was another port on the other side of the manifold for that, but it was definitely connected.

Which brings me on to another point: I have the vacuum unit from a late 316 dizzy here in front of me, the advance seems to work as it should, but the retard doesn't do anything, wont even hold a vacuum - is is broken? I have another to test sat in the car at the moment - will try later....

Does anyone have any experience of simply disconnecting the vac retard on a known working one - any effect? If it can be disconnected, should it be plugged or left open to atmosphere?

Cheers,

Al

Cheers mate.

Mine has nothing connected and is open to atmosphere, doesn't seem to do owt (runs alright anyway) from what I can tell but it doesn't look right and that annoys me!

Tested the one in the car, also seems to have no effect.

i have two vac ports on inlet manifold
one seems to T into the crankcase breather
the other i dont know where it goes


my question is -
should i just blank off all from inlet manifold and then just have one pipe from weber carb to dizzy?
my weber is from E30 btw