weber carb and pertronix ignition upgrade

74soup · 19 February 2009, 22:17

i recently upgraded my 74 super with these items, and now i am having issues. can someone help please?

Bookwus · 19 February 2009, 23:56

Hiya 74,

Welcome to VWAR.

We just might be able to give you a hand with the Weber and the Pertronix. Mostly we deal with stock set-ups but we have some knowledgeable folks around who I'm sure can share some of their knowledge.

What seems to be the problems?

74soup · 20 February 2009, 04:15

well, i was having some issues getting it to shift at all,but upon further inspection, i found a blown vacuum hose. now it shifts, but im getting some thump going into gear. i adjusted the servo and clutch free play before i found the hose, and now i just might have it over adjusted. this stuff is all new to me. i just bought the car a few months ago, and it was someone elses project. about 60% completed. any tips would be appreciated.

greenghia · 20 February 2009, 05:15

Hello, Uh ohh, Weber carb. You are probably going to have to find a spot to get a vacuum signal from above the throttle butterfly on that carb. That is where it comes from on the stock carbs and the control valve needs that signal to shift correctly.

If you are running off a port that draws vacuum from below the butterfly you will have too much vacuum and it is unlikely the control valve can be adjusted enough to compensate(shift smooth). Maybe someone here has run a weber and can tell you how or where they fixed it? I have heard, at least second hand, that someone has run dual carbs and found a way around the vacuum situation but I don't know who they are. Good Luck!

volkenstein · 20 February 2009, 10:17

74Soup,
What flavour of Weber? What distributor is that Pertonix unit in?

SK has rejoined (Stenis to us longtime forumites) and he runs a Weber Progressive (32/36 DG or DF) and a 009. He successfully modified the Weber to actuate the control valve and runs (ran?) a home brew 009 set-up.

If you have a Weber Prog, PM him. On his last post he was chasing jetting info and I told him that subject was being discussed very recently on TheSamba.

If it's a centremount IDF....you have your work cutout for you!

HTH
Volkenstein

74soup · 20 February 2009, 14:27

it is a 32/36 progressive. the pertronix is on the stock vac. advance distributor.

Bookwus · 20 February 2009, 15:45

Hiya 74,

Centermount Webers have their own set of unique problems and these problems are not at all limited to AutoStick applications. There is usually a devil of a time making sure the Weber stays warm enough to function properly. In any event you most certainly do want to contact SK (Stenis) about his experience with a Weber. The information about tapping it for a vacuum source alone will be worth the effort. And you shouldn't have a problem reaching him. He just checked in with us not too long ago.

sk · 20 February 2009, 19:32

74soup · 20 February 2009, 22:19

exactly what i needed to see. what size drillbits did you use?

sk · 20 February 2009, 22:39

Don't remember, I can try to measure on the bug tomorrow. The pin in one of the pictures fits the bore loosely, and is a standard mig welding wire.

/S

74soup · 21 February 2009, 19:15

im not sure whats up here but this is where my vacuum line is already going to. are you saying that i just need to drill the hole out bigger? or did your carb come with no vac. hole there at all? also is it ok to T into that line for distributor vacuum?

sk · 21 February 2009, 22:16

Sorry, I've not been in the garage today to measure the new vacuum port. But let me comment on the pic's:
DSC00697.JPG Pull the existing brass sleeve out of the carb housing. Be careful not to put too much pressure on the pliars.
DSC00699.JPG With the sleeve out you can see that the vacuum port is not simply a straight-thru bore.
DSC00700.JPG Make it straight-thru. I think its 1.5 mm, but could also be 2mm. I'll check asap.

The idea here is to modify the original vacuum port for the distributor, to be used as vac port for the clutch valve.
The port didn't work very well as distributor vac feed anyway.

No, you cannot use a "T". The vacuum operation for distributor and clutch valve are not compatible. The clutch valve wants no vacuum at idle, and full vacuum at throttle. The distributor wants it the other way, at least the single vac feed type distributor.

So, I am using the dreaded 009 (no vacuum advance), and it works quite good. Some small hesitation sometimes, but no big deal.

74soup · 03 March 2009, 00:40

been a little busy lately, but i wanted to thank you for helping me out everything is now running smooth as butter. now i am having alternator issues, but carb and ignition seem to be worked out. i am so glad i found this site, as i have worked out a few "bugs" from reading old posts. keep up the good work auto owners.

bruce_childress · 27 April 2009, 21:35

Quote from: sk on 21 February 2009, 22:16
Sorry, I've not been in the garage today to measure the new vacuum port. But let me comment on the pic's:
DSC00697.JPG Pull the existing brass sleeve out of the carb housing. Be careful not to put too much pressure on the pliars.
DSC00699.JPG With the sleeve out you can see that the vacuum port is not simply a straight-thru bore.
DSC00700.JPG Make it straight-thru. I think its 1.5 mm, but could also be 2mm. I'll check asap.

The idea here is to modify the original vacuum port for the distributor, to be used as vac port for the clutch valve.
The port didn't work very well as distributor vac feed anyway.

No, you cannot use a "T". The vacuum operation for distributor and clutch valve are not compatible. The clutch valve wants no vacuum at idle, and full vacuum at throttle. The distributor wants it the other way, at least the single vac feed type distributor.

So, I am using the dreaded 009 (no vacuum advance), and it works quite good. Some small hesitation sometimes, but no big deal.

neat stuff there, but i always use the svda only, so i wouldn't want to kill my dizzy advance.
i have a dfev and dgev, (also 30pict3, 30/31), but right now i'm using the dgev, so i'll follow your pictures, thanks, but probably find a different place to drill

72SuperAutostick · 12 July 2009, 01:13

That's what I want to do. Run a Weber Progressive. Since my Bug has an EGR valve, is there a spot on the carburetor where I can tap a vacuum line for the EGR?