'74 tii vacuum advance connection

[ingraham]

To what does the other end of the distributor vacuum advance hose connect?

[jfutral]

I don't believe there is a vacuum advance on the distributor for a '74 tii.

(not on my two anyway)

[_z_]

its a vacuume retard distributor that kicks in when decelerating to try to keep emissions down.

here are some pics that might help

http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/t,273375/highlight,tii+vacuum/

http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/t,85230/highlight,tii+vacuum+retard/

The hose goes to the airbox (I think.. mine is retrofitted too so just from memory)

[ingraham]

Thanks very much.

[TobyB]

I think _z_ is right...

... but if the canister is the one I'm thinking of,

it has ports on both sides, and you're only supposed to

hook up the RETARD side to...hmmm... the airbox doesn't make sense... sure it's not the the intake mainfold proper???

...but if your dizzy's been changed to a vac. advance unit, you want to hook it to the port at the base of the carb- that gives no vac at idle, but as soon as you crack the throttle, it'll advance the timing for 'improved power and efficiency'- works great, actually, when it works right...

fwiw,

t

[Andy74tii]

The pics in the links are of my car, and describes what I did to remove the decel valve. If I recall correctly, the vacuum went from the intake to the decel valve, which is mounted on top of the airbox. Then, a smaller vacuum line went in a Y to the retard mechanism on the side of the distributor, and also back to the intake, which completed the vacuum circle. So, I don't think it ever actually went to the airbox, but just the decel valve connected to the airbox.

[_z_]

The pics in the links are of my car, and describes what I did to remove the decel valve. If I recall correctly, the vacuum went from the intake to the decel valve, which is mounted on top of the airbox. Then, a smaller vacuum line went in a Y to the retard mechanism on the side of the distributor, and also back to the intake, which completed the vacuum circle. So, I don't think it ever actually went to the airbox, but just the decel valve connected to the airbox.

ya now that I think about it you are totoally right. At one time I had a really groovy diagram of the whole 74tii vacuum system,,, hold on lemme look

ya.. c.diesel posted these at one point

so is it the T junction labeled #7 (and the line labled #6) in the figure above that goes to the distributor?

Fantastic pics of your car BTW.. it looks to be in near perfect condition.

[Andy74tii]

Yes, that is exactly right, the line labeled 6 goes to the distributor. Thanks for comment on the car; it's in really nice condition still, especially considering it is my daily driver, now with about 38000 miles since the restoration.