Pierburg strip down, probs found

[panzer]

To try and sort the rough idle and over fueling I have started to strip out the 2E carb. Inside the autochoke there is a spring type affair which is possibly a heating elemen,t what the hell does it do and would it effect running? as this is broken up.There are perished also vaccum pipes under the carb so I need to try and source some of these, is there a particular size?

[james butler]

i believe the spring is connected to the coolant and adjusts size accordingly to the temp of the coolant which brings the choke on and off.
because yours is broken you will need a new one or convert it to manual choke, there used to be kits out there to do this to pierburgs.

the vac pipe just needs to be genuine vac pipe as you dont want it collapsing in on itself under vacuum, ive no idea what size it is so take the old stuff off and measure the internal diameter off the pipe and order some new stuff.

[marcus]

<duplicate deleted>

[marcus]

Inside the autochoke is a bi-metal coil of flat section which operates the choke lever.

This coil is heated not only by the coolant (which flows around the housing but doesn't enter the part where the coil is) but also by a small spring-like electric element on the inside (dry side) of the housing, which looks much like a biro spring turned into a near circle.

The bi-metal coil is made of two different metals sandwiched together, which expand at different rates when heated. As the coil is heated it expands and unwinds, opening the choke flap.

Is it the larger coil of flat material which is broken or the smaller 'biro' heater spring?

The vacuum tubing you need is available from VW Heritage:

https://www.vwheritage.com/shop/N020291 ... -3mm-wall/

[panzer]

Thanks, It's the "biro spring element" part that is broken , the bimetal spring is intact. I'll order some vac pipe but am on the lookout for a spare pierburg with this part intact