New carburettor?

[rosie]

I replaced the original Pierburg carb with a Weber about 15 years ago.

I’ve had problems with it ever since. My mechanic says that the flange it sits on keeps deteriorating and allowing too much air in. We replace the flange, it runs ok for a year or two, then starts playing up again.

Currently the revs are all over the place, I stall every time I brake for a roundabout or junction, and I have to constantly pull the choke in and out to keep it from stalling. It’s getting a bit distracting and dangerous.

My usual mechanic has died but before he died he said something like ‘You could get a new carb kit and all your problems would be over’ and said it would cost several hundred pounds. But that’s all he said.

I’m considering taking the car to a carb specialist and possibly getting a replacement because I like the sound of all my problems being over, rather than this continual patching up of the existing carb.

Does anyone have any thoughts on this please? Anyone know what he may have been referring to? Before I speak to the carb people I’d like to have a vague idea of what my options might be. Thanks!

[RussGLAuto]

Some checks before committing - not an easy one to solve.

Even the smallest particles of rust can affect the carb. Has the engine bay fuel filter got black particles in it?

Has the fuel neck been replaced?
Is there any rust particles in the fuel tank?
Are Hard fuel lines under the drivers side of the car clear of rust inside?

The above is what I had to replace to ensure a clean rust free fuel supply after the original mild steel filler neck dumped itself into the tank.

I then had Bromyard VW refurbish and replace the original Pierburg carb.

https://www.bromyardvw.co.uk/

My 82 GL now runs beautifully. Starts first time every time as per the owners manual.

Good luck, Russ

[mark1gls]

Are you still using the original airbox?
Is there a bracket on the front of it fitted to the rocker cover?

I would check the rubber flange which the carb sits on again as they can easily split especially if you don’t have the bracket on the front or if the air box has been bent down to fit onto the bracket, the Webber is slightly taller then the Pierburg and I’ve found that a bigger washer is needed to fix it to the bracket.

You can buy a Webber service kit online for just under £38 but as mentioned check the fuel filter for any bits in it and replace the little filter every 12 months, check the filler neck and tank for rust.

https://www.ebay.co.uk/itm/361073073190 ... R77_9tfSYg


Fuel filter that needs to be replaced every year.
https://www.eurocarparts.com/p/bosch-fu ... -503440077

[mark1gls]

Just looked at your post on the coolant flanges and if the picture is your engine then there is a bracket on the front of the air box, the airbox fixing does look to be at the very bottom of the U shaped bracket holder so it could be pulling on the rubber carb flange.
If you are having to pull the choke out to stop it stalling then the carb is getting to much air and your adding extra fuel to keep the engine running which does make me think the flange has split?

[rosie]

Thanks guys.
I’m certain that the flange has broken because it happens every year or two - gets replaced, and then breaks again.
I’m wondering whether there’s a better option than the current carb with its constantly deteriorating flange, but like you say, maybe it needs a bigger washer or repositioning in some way so that the flange isn’t out under stress.

I had a new fuel tank and filler neck a couple of years ago, and the fuel filter was replaced 9 months ago.

I relied on my mechanic to deal with it previously but now he’s gone I’m going to take it to a carb specialist and hopefully get it fitted and set up properly, or potentially refurbed or replaced. My previous mechanic said that the flanges were made of inferior material and that’s why they kept deteriorating, but he also talked about making a bracket to hold the carb differently, I think to minimise movement.

I provided my previous mechanic with a refurb kit but he said it was the wrong one so I guess I don’t know what I’m doing! I think it’s time for the specialist after 15 years of it playing up.

[rosie]

The picture on the other thread is my engine, and yes it’s still the original airbox

[mark1gls]

It could be the way the carb is fitted or accelerator cable to tight and pulling on the carb when you floor it as something not quite right if you are needed to replace it every couple of years.

Have you tried different manufacturers/sellers of carb flanges?

I’ve had 2 carb flanges split in 20 years so it does happen but should not be a yearly event.

I have seen some carb flanges made out of aluminium so that might be another idea… I’ll try and find them and post a link.

[james butler]

i changed mine out for a weber due to issues with rust ingress in the pierburg
but i also made a alloy carb flange for the weber to sit on instead of the rubber type that does continually split
a bakerlite spacer helps with any heat transfer issues and haven't had it split again
i still make them from time to time when stocks available but you should be able to make one from some 10mm alloy plate
the beauty of the alloy plate is you can also port it to the size of the webers venturis and the manifold as the rubber one restricts a LOT of flow!

[RussGLAuto]

The culprit on mine was the under chassis fuel lines clogged with rust. Have these been replaced?

Classic VW has Mk1 Golf replacements - same as Mk2 Scirocco.

https://www.classic-vw.co.uk/mk1-golf-c ... 8018-p.asp

It doesn't matter of your running the original Pierburg or an after market webber. If the fuel is contaminated, both will struggle.

Pierburg is best.

[rosie]

Fashioning my own alloy flange sounds a bit beyond my current skill set, but I will definitely be mentioning all of this to my mechanic.
Thank you for all your suggestions.

[mark1gls]

I’m sure there’s a market out there for aluminium carb flanges as lots of water cooled VW use the same flange…
We need some one to make some and sell them….

Just a thought…

[james butler]

I’m sure there’s a market out there for aluminium carb flanges as lots of water cooled VW use the same flange…
We need some one to make some and sell them….

Just a thought…

trouble is cost
i was making them but cost of materials, labour and machining takes it well over the £100 mark
most dont want to pay more than £30
but it would be easy for someone with cnc technology
also i have heard a better flange that fits our manifolds and bolts up to the weber a treat is a certain model bmw e30 that uses a rubber flange between carb and manifold (i havent actually tried one so buyer beware!)

[james butler]

https://www.ebay.co.uk/itm/173601455341 ... 77_777_777

[rosie]

trouble is cost
i was making them but cost of materials, labour and machining takes it well over the £100 mark
most dont want to pay more than £30

I would pay £100 right now for a magic flange to make all my carburettor problems to go away!

[james butler]

trouble is cost
i was making them but cost of materials, labour and machining takes it well over the £100 mark
most dont want to pay more than £30

I would pay £100 right now for a magic flange to make all my carburettor problems to go away!

pm incoming