Vacuum advance on dizzy

Bizarre Moderator The artist formerly known as blue74l

12,789 posts · joined Aug 2002 · 14 Jul 2012, 5:55 pm

#912623

My mates bug has hesitation on acceleration

The vacuum advance doesnt seem to be working enough.
How free should they move???
There is suction from the carb - but you have to suck hard to see any movement on the distributor.

If you suck really hard the engine seems to rev easier

So - should the more easily with just a light suck or are they fairly resistive??

Futue te ipsum!!!

shokwave2 Officially Full-On Dubber

289 posts · joined Mar 2010 · 14 Jul 2012, 6:58 pm

#912633

Mine moves easily if you suck on the hose from the vac advance. Does the advance if hold if suction is held with your tongue? If it doesn't hold then the vac cannister is stuffed. If it takes a fair bit of suction to get the advance to move you may have to give the distributor a bit of a service and re-lube the moving parts.

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 15 Jul 2012, 12:16 am

#912682

remove the vac can from the dizzy and suck on the little tube. The cans armature should move in nice and easy. If not the diagraphm may have a small hole.

Now manually check to see if the dizzy vac plate rotates freely with your fingers. If not then use WD40 and wiggle it back and forth till it frees up. If it don't free up you'll have to remove the vac plate and clean the spindle and vac plate bush up as may be a bit rusty 😉

madness is in the eye of the beholder 👍

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 15 Jul 2012, 9:23 am

#912702

Is it a new replacement distributer or an original Bosch/VW unit? Many of the new units are extremely bad quality. If VW, check the part # matches your engine. You could post details here or do the research. Not all vac distributers are created equal. The vacuum signal varies between engines as there are many MANY variables.

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

Bizarre Moderator The artist formerly known as blue74l

12,789 posts · joined Aug 2002 · 15 Jul 2012, 12:18 pm

#912720

Matt

This is a pretty original matching number 1975 R&P L bug - just in a pretty sad sate.
It has sat for a long time but it has real good bones

Its his son's bug so I dont get much chance to look over her.
I have dug up a 009 that they can try and then I can have a good look at the other one and see what the matter is

You had to suck a lot harder than what the carb was to get any sign of movement from the dizzy

Futue te ipsum!!!

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 15 Jul 2012, 5:27 pm

#912764

Bizarre wrote:My mates bug has hesitation on acceleration

The vacuum advance doesnt seem to be working enough.
How free should they move???
There is suction from the carb - but you have to suck hard to see any movement on the distributor.

If you suck really hard the engine seems to rev easier

So - should the more easily with just a light suck or are they fairly resistive??

sounds like the vacuum isn't working OR
what happened to Me on two occasions ;
the accelerator cable had slipped in the collar on the carby
as its always well oiled and the new screw I used didn't grab too well on the cable end... so NO vacuum advance..!!

OR the vacuum unit is cracked due to wear...

and its actually running like a 009 dizzy... does..

the inside of a distributor should be oiled at least when the oil is changed... just a couple of drops..
some dizzies have an oil felt in the centre under the rotor..
which should be oiled too..

New vacuum units can be bought... some are expensive..
should say.. most... lol
there is a number on the vacuum units arm...

I am running a new Bosch SVDA distributor from aircooled.com in the USA... I thought My German Bosch 009 was working OK , until I changed over... YIKES
A BIG difference in advance....
and so smooth on acceleration.... well worth the change..

LEE

- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 15 Jul 2012, 9:54 pm

#912827

Bizarre wrote:Matt

This is a pretty original matching number 1975 R&P L bug - just in a pretty sad sate.
It has sat for a long time but it has real good bones

Its his son's bug so I dont get much chance to look over her.
I have dug up a 009 that they can try and then I can have a good look at the other one and see what the matter is

You had to suck a lot harder than what the carb was to get any sign of movement from the dizzy

The dissy is regularly the wrong one, so vac signal may or may not match the distributer. The part # and engine # will verify. As stated the advance mechanism needs to be operational and free in it's movement, but if the advance is siezing they tend to not return to inital advance easily as the springs aren't super strong to return the advance plate.

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 16 Jul 2012, 1:20 pm

#912885

Bizarre wrote:Matt

This is a pretty original matching number 1975 R&P L bug - just in a pretty sad sate.
It has sat for a long time but it has real good bones

Its his son's bug so I dont get much chance to look over her.
I have dug up a 009 that they can try and then I can have a good look at the other one and see what the matter is

You had to suck a lot harder than what the carb was to get any sign of movement from the dizzy

That's why I wrote what I did. Yes the dizzy has to match the engine but you shouldn't have to suck that hard to get movement.

Search the web for the few sites that list dizzy numbers to engines and year of production.

if it's been sat a good while I reckon the vac plate is sticking.

madness is in the eye of the beholder 👍

BRUTUS Officially Full-On Dubber

255 posts · joined Feb 2006 · 17 Jul 2012, 5:01 pm

#913074

There is a place in Melbourne that I have had repair/reco advance units in the past... If you have an original one and want to keep it. I think I gave the details once before.

Ah. Here it is/was:
"... old dsitributors can be fully recoed/refurbished to original spec's, in Melbourne. Also the vac units can be done - are sent away for rebuilding (takes longer as they send them elsewhere).
At: Performance Ignition Services, Nunawading. 03 9872 3644
This may cost as much or even more than the new-cheap unit, but should give a "good as neu" and hopefully original-Deutsche unit (if you have the correct one in rebuildable condition to start with).
Have had two done so far and have been very pleased with results."

ACE 30 & 40 oils: specifically engineered for your Air Cooled VW
delivered (free del.) throughout Yarra Valley / Ranges, & Gippsland areas. Also ACE 20, 50 & 90.
FOR SALE: ACE 30, 40 etc. Oil formulations & Trade-names.

Bizarre Moderator The artist formerly known as blue74l

12,789 posts · joined Aug 2002 · 17 Jul 2012, 7:30 pm

#913129

Thanks Brutus

The 009 has made a world of difference - that is scary.
So there is obviously a problem with the unit

I have asked my mate to bring it in to me and give me the engine number

Futue te ipsum!!!

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 17 Jul 2012, 8:18 pm

#913159

Bizarre wrote:I have asked my mate to bring it in to me and give me the engine number

You may want him to get details of carb as the engine number these day's won't guarantee what carb and displacement the engine has.

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE