Having only got the Polo back on the road recently it was tuned up by a local garage and running like a dream. The carb flange was replaced last year with a Topran one from Heritage, but I've only covered around 200miles since I got it back on the road in May.   It was all I could get at the time and I know the quality can be hit and miss. 

 

Lastnight after driving it for around 20mins it began to idle roughly and stall at junctions. When driving it was going great.

 

Does this sound like the flange is maybe starting to go? I haven't had a chance to check it yet, but was starting to look for a good quality flange and a mate had directed me towards these guys.

 

https://www.webcon.co.uk/products/10136-rubber-mounting-block-3134-pic/

 

VW classic parts list two with the same 030129765 part number, but have a D and a G at the end (mine is C) so I'd assume unsuitable. 

If it’s a 030129765C part number that will be for the 1.0HZ engine with a Pierburg 1B3 or a Weber 32TLA.

 

Your webcon link seems to show one for  earlier Solex Carb, but none for the above carbs.

 

I’ve had 3 pattern flanges fail before in a matter of months, from varying sources.I’ve got another one to try from JP Group, as funnily enough mine has just failed again today, which was the original genuine VW one, but was bodged with paper gaskets after all the bother I had with the pattern ones. It lasted another 6 years like this.Today the engine wouldn’t idle and was stuttering quite badly unless I kept the revs up. I managed to get it home as luckily it went only a mile from home.
 

I’ve also previously  found that the Carb mounting bolt holes were actual inserts and that they can pull out of the top main metal plate that makes up the flange.This may have been me over tightening the bolts, but it clearly is a something to watch for, especially if it is at fault and has only lasted 200 miles.

 

Seems no one can produce the flange as good as the originals, hence them only lasting months rather than years.

Edited 24 August, 20215 yr by mk2tastic

Could the idle jet be partially blocked by dirt?

 

Thin bead of blue hylomar as temp repair?

 

Wonder if it would be worth glueing the inserts in the rubber?

 Super glue

or Vinyl glue for wetsuit repair perhaps.

 

Should not come into contact with petrol when fitted.

 

  

Edited 25 August, 20215 yr by dvderlm

The carb and lines were all well cleaned out a while ago, I'm maybe paranoid about the flange as wasn't confident of the quality. There's a place on ebay with genuine ones apparantly, in Latvia, has anyone had any experience of them? £88 plus postage. 

https://www.ebay.co.uk/itm/133582449502?hash=item1f1a226b5e:g:4XoAAOSwlOJft5Cn

 

This is another brand, vaico?

https://www.ebay.co.uk/itm/383767696646?epid=11017004810&hash=item595a565506:g:L4wAAOSwzlxfzT08

Edited 25 August, 20215 yr by Jim1500

Well after my failure yesterday with no idle and rough running, it turned out not to be the Carb flange after all!

 

The brown wire that runs from the carb to the engine block for the carb earth had come adrift, so my idle cut off valve wasn’t operating!

 

 I ended up re-crimping the ends as the wire was about to break anyway, plus it was slack on the block end connector.

 

Still think I’ve got a very slight leak from the flange, but I’m hanging on as long as possible before replacing the genuine one with a potentially poor quality replacement..

Edited 25 August, 20215 yr by mk2tastic

If a Pierburg 1B3, the throttle body heater would also not have been heating the part channel for better fuel vapourisation.

 

Part  36

http://www.gowerlee.dircon.co.uk/1B3type.html

The number of times a running condition has been down to a shoddy or missing earth. Sometimes I feel like Polo engines are just a collection of earth straps, the internal combustion is a secondary extravagance

Ok, had it out lastnight again, drove it a mile or two and put £10 in before heading down the motorway a few miles, a bit of town driving then back up the motorway again and it idled perfectly. I even took it up a carraigeway at 50mph and brought it to a stop at a roundabout and again no stalling. I'm wondering was there maybe less fuel in it than the gauge was telling me (new tank in).

 

I still want to source a decent flange is it's always going to be in my head that the Topran one will fail. 

if i owned a carb model i would be looking at buying a scrap of aluminium and making my own flange , or getting it drawn up for a machine shop to make  , bit of gasket paper either side and its permanent fix