Mystery Diaphragm

[juno106]

Hello.

Just bought a new Solex Z1 32/34. Im confused as to what this extra diaphragm is for on the front, below throttle cable bracket as its not fitted to the carb curently on my car.

Any ideas?

Thanks.

Matt.

[Tinkley]

I have 2 Z1 32 34 s' and I don't have that weird attachment. It may be a way of setting the idle stop from the front not the rear. It looks like one half of the autochoke mechanism but adapted to take the threaded screw.
I take it it is an autochoke model, if not it may be for a manual choke attachment. It's not the same as the RCK33 kit which is still available for auto to man conversion.

[juno106]

Hi.

Thanks for the reply.

Yeah its an autochoke.
I had a guess that it might be something to do with idle. It does have an idle adjustment at the rear where you would expect it though.

I might just remove it, or leave it there and ignore it unless it has an adverse effect on the carbs operation once I fit it, in which case I will perhaps contact Webcon, who I bought it from to ask for some advice.

[citronut]

it might be and anti flood/strangle capsule,
similar to a dersh ( 2CV ) has,

you should be able to tell what it does firstly by following the rod at the back of it,

or attach a length of pipe to the spout and suck on the pipe whilst watching the mechanism,

regards malcolm

ps.

hope you dont get grease on your mums sofa

[juno106]

it might be and anti flood/strangle capsule,
similar to a dersh ( 2CV ) has,

you should be able to tell what it does firstly by following the rod at the back of it,

or attach a length of pipe to the spout and suck on the pipe whilst watching the mechanism,

regards malcolm

ps.

hope you dont get grease on your mums sofa

It appears to pull againts the throttle mechanism, which would back up your suggestion of its purpose. I know what you mean about 2cv carb as I've got a Dyane back at my home in N. Ireland (currrently reside in Glasgow).

I think I'll have a go at connecting it up if I can get my hands on a suitable T-piece to splice with the vacuum advance pipe.

ps.

In respose to your concerns over upholstery. Thats my lap the carb. is resting on, i.e beige trousers, not beige sofa

Matt.

[electrokid]

If that's a vacuum connection to the plastic housing it could be an anti-stall mechanism.

If the engine revs fall close to zero the vacuum also fails - a diaphram previously held by the vacuum against a spring is released when the vacuum fails and either operates a lever to pump fuel directly into the carb or the carb side of the diaphram (as opposed to the vacuum side) is the pump itself and the diaphram movement pumps fuel into the carb and prevents the stall.

[kiwi]

I forget what the thing is called but it is on the Aircon models and is part of that function I am lead to believe. I know some fiddling with it while running the aircon on adjusts the idle.

It IS fitted to both Aircon models of my 19TZS fleet but not fitted to the 19TRS infact I have never seen it fitted to any other BX petrol unless its got aircon.

Will have a look tommorow for you to see how it conects and if you can indeed not bother with it, my hunch is you dont need it.

[citronut]

I forget what the thing is called but it is on the Aircon models and is part of that function I am lead to believe. I know some fiddling with it while running the aircon on adjusts the idle.

It IS fitted to both Aircon models of my 19TZS fleet but not fitted to the 19TRS infact I have never seen it fitted to any other BX petrol unless its got aircon.

Will have a look tommorow for you to see how it conects and if you can indeed not bother with it, my hunch is you dont need it.

i think this is more likely the correct answer,

so yes also anti stall,
and if so it will bring the rev's back up whilst the air con pump is running

regards malcolm

[juno106]

Thanks for the help.

Much appreciated.

Matt.

[kiwi]

I looked on the 19TZS with it fitted and it is part of the aircon.

Basically the tube out goes over to the passenger side to another gizmo attached to the bulkhead under the battery tray with a couple wires attached to this gizmo. Another tube then runs back to the front of the carb, directly behind that Diaphram.

On the non aircon models that tube on the front of the carb is blanked off. Is that the case with yours? I have no idea if just directly pipining from the diaphram to the carb port will affect your carb operation.

Be interested in the solutions you find to this.

[electrokid]

I looked on the 19TZS with it fitted and it is part of the aircon.

It was common at one time to operate aircon components (pump clutch, coolant valves etc) by a vacuum switch in the dash. In this case the vaccuum (switched to that port when the aircon is switched on) is obviously used to change the idle setting on the carb so the car doesn't stall when the aircon is running and adding a small extra load on the engine.

So when vaccuum is applied to that port the revs will increase slightly - that's the opposite of an anti-stall arrangement where revs are increased when the vaccuum fails

So if you don't have aircon it's best to ignore that assembly altogether.

[Tim Leech]

Ive had a few 1.6/1.9 carb fed cars but never seen that before. Be interesting to see how well it runs with a new carb!

[juno106]

Just fitted the carburettor tonight. Runs like a dream. No more horrible flat spots and the throttle response is greatly improved.

[kiwi]

Yes but how did you deal with the ports of the diaphram and on the front of the carb??