What should be connected here?

Post by **asahartz** » 15 Sep 2008, 16:37

Had a stalling problem on my bus, so I cleaned out the carb (seems better now).

However in the process I noticed a vacuum connection on the carb which doesn't seem to have anything connected to it - there are no stray pipes anywhere, but I connected a tube to it and there is definitely vacuum there so it's not a blank.

For the time being I've blocked it off - a tube allowing unfiltered air into the carb is obviously not a good thing, but what should be connected there? My HBOL gives no clues.

It's the one arrowed in this pic:

[img:800:600]http://www.b0lus.com/images/cars/vwcarbvactube.jpg[/img]

Post by **Mocki** » 15 Sep 2008, 16:41

it should be connected via a "t" or a "X" connector into the rest of the vac advance vac pipes, that go to the dissy iirc

Post by **toomanytoys** » 15 Sep 2008, 16:41

Pic of Dizzy would be handy...

Could well be the vac take off for the vac advance on the side of the dizzy....

Post by **asahartz** » 15 Sep 2008, 17:30

Now I'm even more puzzled then. There is an x-connector, but that has two pipes going to the side of the carb, one to the air cleaner, and one to the dizzy.

More pics:

[img:800:600]http://www.b0lus.com/images/cars/vwcarbvactube2.jpg[/img]

[img:800:600]http://www.b0lus.com/images/cars/vwcarbvactube3.jpg[/img]

(The red-arrowed one here is my blanked-off pipe)

Post by **Mocki** » 15 Sep 2008, 17:49

ok, took me a while to dig them out, but i have pics of a df

[img:640:480]http://www.club80-90.co.uk/techhelp/dfvac.JPG[/img]
[img:640:480]http://club80-90.co.uk/techhelp/dfvac2.JPG[/img]

the pipe you are missing goes to the dissy, i was half right!!

Post by **asahartz** » 15 Sep 2008, 17:54

Hmmm... is my carb different then? (Solex 34PICT) That pipe on mine goes to a connection at the bottom of the float chamber which doesn't seem to exist on yours (bottom left of first pic). This is a DG btw.

Post by **Mocki** » 15 Sep 2008, 18:34

ummmm.. not sure then, thats the only pics of a simular carb i can lay my hands on, and its a DF, not a DG in my pics....looks the same from here

yours isnt a DG carb, for they are pierburgh (SP)

Post by **asahartz** » 15 Sep 2008, 19:17

That doesn't surprise me, my bus is quite a mixture of bits in that department. The air ducting on top is clearly not for that carb as the fixing screw hole doesn't line up with anything and I use a bungee strap to hold it in place!

The exhaust is an EMPI Quiet Pack - which is an Aircooled exhaust, but it seems to have had custom pipework made to connect to it. Matt at Justaircooled said he's never seen one like it. But it's done well.

Mind you - Quiet Pack? If that's quiet I can't imagine what a Noisy Bugger would sound like!

Post by **Mocki** » 15 Sep 2008, 20:36

if the engine number says DG you should really be looking for the right inlet manifold and carb to get the most out of it..........

Post by **toshT25** » 15 Sep 2008, 23:31

Took these pics of my 1.9 DG (Solex 34PICT -5) last year if they're any help.

[IMG]http://img519.imageshack.us/img519/4056/42hv8.jpg[/img]

[IMG]http://img403.imageshack.us/img403/1903/81179827kp5.jpg[/img]

[IMG]http://img519.imageshack.us/img519/1357/61132079yn9.jpg[/img]

[IMG]http://img359.imageshack.us/img359/4783/16481643fz4.jpg[/img]

[IMG]http://img144.imageshack.us/img144/5802/60511631ik4.jpg[/img]

Post by **asahartz** » 16 Sep 2008, 16:19

Mocki wrote:if the engine number says DG you should really be looking for the right inlet manifold and carb to get the most out of it..........

It's definitely a DG. What difference will (I'm guessing it's ) a Pierburg make? And what's different about the manifold?

It does go pretty well, but I've never driven another so I can't compare.

Post by **asahartz** » 16 Sep 2008, 16:22

toshT25 wrote:Took these pics of my 1.9 DG (Solex 34PICT -5) last year if they're any help.

[IMG]http://img519.imageshack.us/img519/4056/42hv8.jpg[/img]

Yours doesn't have the connection on the bottom of the float chamber either... Mine does! Bottom left of first pic.

Post by **asahartz** » 20 Sep 2008, 20:29

Today, given that I am having running problems, I connected the pipe from the dizzy to this vacuum takeoff. It did make a significant difference to the engine's running, though didn't solve it.

So I got to thinking, did I make a mistake and connect it to the wrong place? Apparently not. I dug out some pics I took of the engine back in February, and it was connected to that point on the bottom of the float chamber that nobody else seems to have. And it must have been running since I got it with a naked vaccum takeoff!

However I couldn't detect any vacuum from that connection this afternoon. So the carb's coming off again tomorrow and I'm going to be having a much closer look at that bit...

Post by **asahartz** » 21 Sep 2008, 11:47

Dismantling has helped clear up some of the mystery, though I've still not worked out what's causing the misfiring.

The carb is a Solex PICT34-4 - not even exactly the right Solex! Which is why I have the strange connection at the bottom of the float bowl - it seems that this is a vacuum-operated valve to allow fuel to the accelerator pump. So it needs a vacuum connection, but is not a source of vacuum itself. Which means my carb has been connected wrong ever since I've had it...

Come to think of it, there have always been occasional stalling problems, but not regular enough to give me real grief. Until now.

Post by **asahartz** » 21 Sep 2008, 19:14

asahartz wrote:
Mocki wrote:if the engine number says DG you should really be looking for the right inlet manifold and carb to get the most out of it..........

It's definitely a DG. What difference will (I'm guessing it's ) a Pierburg make? And what's different about the manifold?

It does go pretty well, but I've never driven another so I can't compare.

And more info comes to light! Just checked the the V5C and it's registered as a Transporter 60PS, with a DF engine number. But I definitely have a DG in there, though I've yet to check what heads are fitted - manifold will have to come off anyway, but would a casting number identify the heads first? If I have DF heads there's little point in sourcing a DG manifold is there?