VWAR Old forum !

I know there has been a thread before on bumpy gear selection from stationary and a very explicit answer from Bookwus.

Which vac. should I be using: can you tell fron the pic?

Are the three marked positions all vacuum?

I don`t know why but the "restorer" changed my original carb: I am sure there was nothing wrong with it that could not have been sorted.
What is this carb?
The car is `69 beetle auto.

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Raysor,
          That looks like a 34 Pict 3. Who knows why there is a screw there :shock:  Have a look on the fuel bowl on the left hand side (as pictured) it should have the carb designation on it...

On your first arrow..where does that line go? That is for vacuum retard on a DVDA distributor.

The second arrow with the cap on it should be your control valve feed.

To test that your "restorer" has done their homework....

Start the car and let it idle. Remove that cap (second arrow) and place your finger over the hole...there should be almost zero vacuum. Rev the car, you should now feel vacuum. If you do, this is where your control valve feed plugs into.

With the DVDA port, if you run the same test you'll have a lot of vacuum at idle but as soon as the throttle is "blipped", none.

I'll look at my guinea pig carb body later tonight to see what that screw is blocking...


Volkenstein

Thanks Volkenstein.

The pipe on 1/. is going to he servo.

The vacuum advance being used is to the left (and around the corner) of 1/.

I will try your tests later this evening.

Hi Volkenstein,
I tried your test:  The item 1/. gives strong vacuum on tickover and reduces slightly on increased revs. Item 2/. gives no vacuum either way.

Haven`t tested item 3/. yet.

Raysor,
         Please check that carb designation.......as a thought, look on top near the fuel fitting as well. Is it made by Solex, Brosol, Bocar or Kafer/Pierburg??

If indeed it's a 34 Pict 3, I would pull off that cap and shine a torch inside.

There should be about a 1.5mm hole in the fitting which leads to just below the tapered part of the venturi. If you pull your air cleaner off, open the choke and shine the torch into the fitting you should see a light spot in your venturi....

The DVDA port (first arrow) is fed by a closed throttle plate (idle) and retards the distributor to (urrgggh faulty memory) ATDC. When the throttle plate is opened, vacuum is supposed to be nearly zero so the timing advances instantly to 7.5 BTDC


Volkenstein

Volkenstein,

I will check that later- I am working over the `phone to my son at home with the Beetle!

As I say the vac advance is coming from around the left side- you can see the pipe behind the spring. That all seems to be working OK as the engine runs good.

Thanks a lot for your help - it all seems promising.

What you doing up? What time is it in Canberra?

Rayzor,
         Only 10:00 p.m. here at the mo.
Trapped in the study with the computer because we've just mopped the floors :lol:  
I've got  a nasty flu virus and hitting the shed in the cold (winter here) tonight isn't an option.


Enjoy
Volkenstein

Raysor,
         I checked my guinea pig carb body and my Orange Bentley manual.
On the GP and my running carb there is a blank boss there. In some carb pictures in the bentley there is a vacuum spigot on that boss. For your purposes, keep it blocked.


Volkenstein

Hi Sean,
Yes by the look at the photo I would have said the middle line ou as the one that has the hose on,
looks as though it goes up and downwards in the carby casting...
which I think would be incorrect...
Sorry, to hear You have a cold etc Sean,
If I get a cold it gets nasty fast so I take Large does of Vitamin C
and Echinacea capsules..
and I'm better after one day... I can't afford to get sick as I'm an Asthmatic..
On the Cold weather, it was still below Zero at 730am here today...
I'm going outside now to warm up....

cheers

Lee   68AutoBug  Australia

The carb is a Solex H30/31 PICT

What is the outlet no 3 with the pipe and screw?

I am going to have a look inside the carb in a mo as you suggest to see where the holes go to.

The good news this week is I picked up a windscreen washer switch (that operates the compressed air) at a VW show for £1 and it works a treat!
Thanks a lot for your help

Just swapped the pipe from 1. to 2., or my son has.
Seems to be great improvement, should have tried that at the beginning.

Will try adjusting the servo/control at the weekend.

Raysor,
         Well, well, well..three holes in the ground! :shock:

I've never actually seen a H30/31 in the flesh (I'm new to VW's).

When you get it off, you'll see there is a hole underneath the throttle plate in the throttle bore adjacent to the up/down casting for arrow No 1.

I have no clue as to what use the additional vacuum port is for. My blank boss on the guinea pig 34 Pict has a passage that runs around the base and this leads to the drilling for the progression/transition holes.

Does that No 2 fitting look "factory" or something someone has done?  I'm asking as on non-AS 34 Pict 3's....it's just a blank boss and Cobey and Dennis (BTL069) are modifying ones to suit....


Enjoy
Volkenstein

Raysor,
         From the Type 2 library....took me long enough!!!

Quote/

Fifth, Any other fittings on your 34PICT Carb are for the infamous Throttle Positioner sometimes improperly called a "Decel Valve". The fitting for this jewel is an angled one right at the rear base of the carburetor. Connect the small vacuum hose to it to the Throttle Positioner Diaphragm Fitting. If your Throttle Positioner has two fittings (as original on 71 Buses, 71-74 Beetles), connect another length of 3.5mm vacuum hose from that to the Throttle Positioner Solenoid, usually located in the left side of the engine compartment. If you don't have the Throttle Positioner, cap off all the remaining fittings on your carburetor.

If you're running one of those new replacement H30/31PICT carbs, the procedure above is the same as they come with these fittings like their distant 34PICT cousins.

/Quote

You haven't got one...keep it blocked...


Enjoy
Volkenstein

Is that the Dash pot they are talking about?  "Decel Valve"
I saw a pic of one of the US PICT 34 and it had a dash pot which makes the carby run on for a few seconds after You take Your foot off the throttle...
All Japanese cars had them in Australia in the late 70s and 80s...
I used to disconnect or take them off completely...
they are run by vacuum too....
something to do with pollution control...
Never seen one on an Aussie Beetle though...

Lee       68Autobug

What a mine of information-thanks all!
Going to have a good look at the weekend and will post back.

I bought the car in the 70/80`s (have to check) and it was in immaculate condition.
I always used genuine VW bits when needed, so I knew what the original should look like (memory withstanding)
Took it off the road because the driver`s door wouldn`t shut properly and it stood for years imitating a greenhouse.
Unfortunately when the "restorer" did the bodywork he took it into his mind to change the carb, aircleaner and dynamo (and wrecked the pneumatic screenwash switch, replacing it with an electric one! )
Also put on a bonnet without air-intake.

would like to put some original pics and current pics on the forum shortly. Don`t think I have any in the greenhouse mode, though.

Cheers everyone!