Hi Folks

I’ve been having constant problems with my mk 2 1.0 breadvan. When you press down on the throttle about half way down the car almost always cuts out or the power dramatically reduces. Pulling off in it is almost impossible, it never seems to get enough fuel to actually get going.

I imagine it’s a fuelling issue or a problem with the Weber carburettor which I hear is a common problem with these cars.

It idles totally fine and starts up as a 35 year old car would do. I’ve cleaned out the carb so many times now I’m loosing count.

I’ve had the following parts replaced if that’s is any help:

Fuel lines

Fuel filter

Swirl pot / vapour separation

Carb flange/manifold

Fuel pump

Fuel tank (painted in hammerite)

I’m completely stumped with this thing, any help would be massively appreciated as this car was my daily and my first ever car, so I would love to keep it for as long as possible. Just would be nice to drive it.

If there is a thread that already discusses this please please drop a link to it.

Edited 1 September, 20251 yr by Fat Men INC

Sounds like you've replaced the usual culprits.

Might have introduced a vacuum leak at carb flange if new one is split.

Spray cold start spray around the base, see if it changes idle engine note?

Wobble the carb and see if it changes revs?

Sparks all strong, timing correct?

Weber TLM is a good single choke carb.

Half way throttle might be where the main circuit takes over from idle circuit.

Pulling away is idle circuit and pump jet enrichment.

Covering the leanness from idle to main is the pump jet.

So at a guess the pump jet diaphragm has split

(part

47407.249 Weber DGAS/DGAV/TLM/DFE/DFT

has 4 screws

or 47407.306 for the 3 screw enrichment diaphragm to the curved pipe ?)

or that pump circuit inside the carb has a partial blockage.

Edited 6 September, 20251 yr by dvderlm

Found a new TLM for a 1 litre.

You'd need to move throttle cable connection, maybe other parts from your carb.

I assume the base mount is the same and the jetting is close enough, given E5 fuel.

Maybe the main emulsion tube is different for the Fiests.

https://www.webcon.co.uk/products/675-32-tlm-1a1-ford-fiesta-999cc/