[Kingrob015]

Ever since Ive owned my bug i have always wondered what this was and was curious to know, i have tried searching it up with no luck maybe one of u guys know? Its bolted to the fire wall beside the engine (Engine size 1600 if that helps)

 

[JohnNewb]

Can it be a smog pump of some sort? Mine has the bolt holes for one on firewall.

 

[Kingrob015]

it could be it was imported through cali and i think i heard at one point that Volkswagens that were imported into California had to have some smog equipment or maybe its just u.s regulations I'm not quite sure, would it benefit to hook it back up or would it just not be worth it? Theres a line coming from the intake towards it and i am assuming thats whats its for.

 

[JohnNewb]

I would leave it off if car is exempt. Make sure vacuum port is capped.

 

[67bug]

That is a throttle positioner control valve. VW had two styles of throttle positioners.

One type has a plate that goes between the carb and intake manifold which has a vacuum diaphragm, with a linkage that attaches to an arm next to the throttle arm. It will have one or two vacuum lines. When vacuum is applied to the diaphragm, it opens the throttle a little, generally when decelerating. This vacuum diaphragm in controlled by the vacuum control in your picture which is remotely mounted usually to the firewall.

The other type is a bit more common. This has the vacuum control and vacuum diaphragm as a single unit, which is is mounted on a bracket that attaches between the carb and the intake manifold. It sticks out toward the engine lid and usually has a vacuum line that attaches to the intake manifold. You see these in 70's era smog controlled engines.

 

[67bug]

If you leave this off your car, you will need to remove the vacuum diaphragm that mounts under the carb base and make sure the throttle positioiner arm on the carb is not restricted in any way. Not sure but you might wire the positioning arm back toward the fan shroud so it does not move at all. You also need to plug any vacuum ports on the intake manifold, near the top of the manifold or on the aluminum dual port adapters, that used to go to this control valve. It is likely you would also have a dual diaphragm vacuum advance distributor. Don't connect anything to the port closest to the distributor body and hook the other port to the vacuum advance port on the carb.

 

[Kingrob015]

Thanks for the info! The previous owners have pretty much done all of that, the vacuum ports are capped and there are no signs that it has been used recently and its running pretty good without it so far, are these usually something that people buy? If so i would be willing to sell it.

 

[JohnNewb]

You could try Facebook or Craigslist or wait and see if anyone here speaks up. We have the toughest smog laws here in California but cars 1976 and older are smog inspection exempt so not much market or desire to have the early smog devices. Not sure how much they are needed with our environmentally friendly crap fuels. I don’t know how to price a part, confitikn unknown either.