Apologies if I’m being an idiot, but I cannot figure out how the choke is set when the throttle is pushed on a pierburg 2e3, I do have a different throttle lever to all the diagrams of the carb I have found, could this be an issue?

Edited 26 July, 20224 yr by Mludford
Added photo

Photo?

Here is an additional photo

The choke cover mechanism acts on the pin you are touching in that finger.

 

Two ways.

 

a)There's a heater element powered by switched 12v. I think this overcomes inertia when very cold.

b) A  bimetallic strip that is spring like. The inner part expands more than the outer part by the conducted heat from the warming coolant and moves the flap as it changes shape.

 

The plastic UFO pulldown unit also acts on the choke flap to crack it open a tad

(gap is specified depending on engine air flow) when cold engine fires by vacuum suction.

1 hour ago, dvderlm said:

The choke cover mechanism acts on the pin you are touching in that finger.

 

Two ways.

 

a)There's a heater element powered by switched 12v. I think this overcomes inertia when very cold.

b) A  bimetallic strip that is spring like. The inner part expands more than the outer part by the conducted heat from the warming coolant and moves the flap as it changes shape.

 

The plastic UFO pulldown unit also acts on the choke flap to crack it open a tad

(gap is specified depending on engine air flow) when cold engine fires by vacuum suction.

I understand how these two elements open the choke once closed, the bit I can’t quite wrap my head around is how the choke is closed by pressing the accelerator pedal before starting

There's a wheel with steps that rotates lifting a tiny cam that the speed screw

pushes against. 

That opens the throttle valve a tad for starting.

 

And the pulldown unit manifold vacuum is lost when engine off so choke flap rests nearly closed (when engine cold). If the pulldown unit diaphragm has split, there won't be enough elasticity for it to pull open or return to rest.

Edited 29 July, 20224 yr by dvderlm

From memory they do sit fully open after an engine that's been run cools right down, and only shut again when 'set' closed by depressing the go pedal on a cold engine.

If I still had one (no chance) in the shed it would soon remind me how the mechanism works, but I guess there's something connected to the choke flap that interferes/interacts with a part of the throttle cable holder thingy which isn't there when the engine is warm, but is when cold. That may be stating the obvious, I suppose.

A guy by the name of RicardoM on Briskoda knows plenty about the 2e3, so a search on that name may throw stuff up, another guy (or same one under a different username) 'masster' on clubgti from a number of years back knew his stuff.  Ricardo isn't known for his tact and diplomacy though.

 

Maybe this bit?

 

Could well be. The 2e2 operation is explained here in dense German.

http://www.ruddies.business.t-online.de/2E2Wirkungsweise.htm

(and 2e2 has a thermotime valve and a waxstat too, just to make it more complex... great carb when in good condition)

 

Section on wide open kick (the only English?) might apply.

Edited 5 August, 20224 yr by dvderlm