Carb Identification and issues

Hello,
I'm new here so forgive me if i've posted in the wrong place, I've just purchased a Mk1 Golf Convertible which ive been told has a Weber carb but i wouldnt know if it is Weber or not and cant find any markings on it identifying it, so if anyone can advise what carb it is i would be very grateful.
secondly the car runs well and starts on the button but when cold it idles at about 800rpm and hunts slightly sounding like the idle needs screwing up slightly but once warm idles beautifully at a tad over 1k rpm. however once you get driving the car pulls beautifully but when slowing down rpm drops and engine cuts outs. this isnt every time but probably every other time. if you blip the accelerator it stops the engine from cutting out but this if very difficult when holding clutch in and braking as i dont have 3 feet nor long enough arms. When it doesnt do it rpm sit just above the 1k mark as per a warm idle. If i manage to keep bliping the accelerator and not crash into the round about the car then pulls away fine and drives perfectly well again. The car hasnt been used for a little while and fuel may be 6 months old so i filled up with super unleaded to dilute older fuel and i'll give the air filter a good clean at the weekend hoping this may help but any advise on what may solve the problem would be very helpful.


 

Do you have a manual choke?


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Its has a manual choke as in i pull it out before starting when cold but it does go back in automatically

I would say it’s a Weber - it looks the same as mine, however the choke should not go back  automatically .


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Also have you checked the rubber base plate for splits - this is a common fault, causing running issues


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I'm planning on taking it off this weekend  and having a look. As you can see on the photos if has something leaking that you can see in the photo on the right of it but cant seem to find where its coming from but when i take off i should get a better idea.

You will always get problems with cold starts because you have have a K&N aftermarket air filter and they have no warm air feed from the exhaust manifold.
You can get problems with carb icing up in cold wether.
As the air filter is sat at the back of the engine over the hot exhaust manifold it only gets hot air unlike the standard air box which has a pipe going to the front of the engine near the grill you can also lose performance as the colder the air the bigger the bang..

Check the rubber carb flange as you are also missing the bracket which hold the standard air box steady at the front of the rocker cover, your carb has nothing to hold it steady other than the flange.

I've fitted a K&N air filter but a panel filter which fits inside the air box..

There’s no need to remove it, you’re giving yourself more work, you should be able to diagnose a split in the flange - with the engine idling push on the carb in all directions while looking and listening, you can spray carb cleaner  around the flange with engine running and listen for a change in engine note - which would indicate the carb cleaner is being drawn in and firing in the cylinders - be careful though obviously - it’s all highly flammable


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I will definitely check this, I think its a Weber 32-36 but not sure so hopefully will also find the model number if i give a little clean. As for the choke, you say it shouldn't retract by itself as it warms up? I'll have a look at this too…

You have a Webber 32/34 DMTL

I guess you have 1.8cc engine?

if you have a choke cable/handle inside the car, you pull it out to start the car and you have to push it back bit by bit once the engine starts to warm, it should not go in/switch off on its own.

The link below is a great company and very helpful, they may be able to help to why your choke cable is slowly returning to the off position?

https://fastroadcars.co.uk/store/index.php?route=product/product&path=60_73&product_id=590

afaik there are carbs that are copies of the Weber - I think I have one on my 1.3 mk2 and it works OK - but I assume it is lower quality somehow than a genuine Weber. Never bothered me but thought it was worth mentioning.



If you can see WEBER written here it's probably genuine I run the standard air filter on my cars with Weber conversion.

About the fuel - I recently found a 5L petrol 'can' that I filled up with super about 6 months ago and forgot about. I thought it would be fine to put in my 1.8 mk2 with a Weber carb on it - car had about 1/4 a tank in it at the time and is a daily. Oh how wrong I was! A 15 minute drive later the car was sputtering, running badly and cut out at idle. I ended up ditching it and walking to the nearest petrol station to get another 5L of new super and managed to get it home - and a few days later put £20 in it and took it for a motorway blast. It took about 2 weeks to clear the randomly cutting out problems. Replacing the inline fuel filter seemed to help.

What I'm trying to say is - even mixing new fuel with old fuel didn't fix the issue immediately for me. I was pretty surprised but lesson learned.

Best of luck getting to the bottom of your issues!