Etienne

Vacuum connection missing ?

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Hello all,

 

looking at my '74 2002tii engine yesterday with a friend, we noticed a vacuum plug on the intake manifold (to the left of the 2nd cylinder, from the right, on the picture below) that was not linked to anything... nor capped like the one between the 3rd and 4th cylinder.

When the engine is running, there's vacuum in there; any idea if that should be connected anywhere ? capped ? When I close it the idle seems to be stabler and lower in terms of rpm.

 

Thanks in advance !

 

Etienne

engine.jpg

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Hello all,
 
looking at my '74 2002tii engine yesterday with a friend, we noticed a vacuum plug on the intake manifold (to the left of the 2nd cylinder, from the right, on the picture below) that was not linked to anything... nor capped like the one between the 3rd and 4th cylinder.
When the engine is running, there's vacuum in there; any idea if that should be connected anywhere ? capped ? When I close it the idle seems to be stabler and lower in terms of rpm.
 
Thanks in advance !
 
Etienne
engine.thumb.jpg.9163ee722154dcd8412befb4d0d59c96.jpg

That line connects to the vacuum retard valve on the air cleaner. From the valve it connects to the distributor and the intake.

28c96d16e7a4b4508989d4927f9dc35b.jpg

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Thanks a lot Danz! But... I've found the connection in another topic (https://www.bmw2002faq.com/forums/topic/204529-why-does-my-74-have-a-vacuum-advanced-distributor/) but I don't have an air cleaner (there's the bracket for it on the air filter though) and I don't see the vaccum connection on the distribution...

So I'm wondering now: should I just buy a cap and can the engine perform well withaout that vaccum advance ? Or else, should I buy and air cleaner, a vacuum pipe (but then where do I connect it on my distributor) ?

 

Thanks !

20180528_182556.jpg

20180525_125835.jpg

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Etienne,

Looks like your engine has been de-smogged.  Mine has also been de-smogged.  Plug all the open connections on the manifold and on the underside of the throttle body.  If you do not have a diaphragm on the distributer then it has been changed out whith an earlier one.  The engine should run fine with the vacuum connections plugged if tuned properly.

Good luck,

Glen

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Etienne,
Looks like your engine has been de-smogged.  Mine has also been de-smogged.  Plug all the open connections on the manifold and on the underside of the throttle body.  If you do not have a diaphragm on the distributer then it has been changed out whith an earlier one.  The engine should run fine with the vacuum connections plugged if tuned properly.
Good luck,
Glen

If I’m not mistaken the deceleration valve was indeed a pollution reduction item. So if all of the parts are missing I assume plugging open ports and tuning properly should result in a good running engine.

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Thanks Glen !

Just one more question: I read here and there in forums that de-smogged engines tend to run better ? (But not necessarily meet the emissions standards). So I am wondering... Should I buy a distributer and plug it properly ? Or should I just cap all the vacuum plug and let it run as is ?

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Etienne,

I would not buy another distributor.  Just plug the open holes and see how he/she runs.  Probably won't meet the emission standards if that is a concern in the state/country you live in.

Best,

Glen

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All right, just bought more vacuum line (ran out of it with my other car...), do you think I should also buy an air cleaner like on the picture on top of that chain or just vacuum line, a tee and it'll do the trick by connecting the 2 plugs on the manifold and the one under the throttle body ?

 

Thanks again Glen !

 

Etienne

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Etienne,

I would not connect vacuum hose to any of those nipples on the manifold or throttle body.  Just put a plug over them.  That is how the tuner set up my fuel injection.  Car runs fine and I don't have to worry about emissions in North Carolina on a vehicle that old.

Best,

Glen

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