Carb issue 1905cc model

kiwi · Post by **kiwi** » Sat Apr 18, 2009 9:44 am

OK guys this Kiwi BX is maddening as to the Carbie layout.

Any ideas what the screw fitting circled does? Theres a pipe from it that goes under the battery tray to some gizmo connected to a couple of wires then another pipe head into the carb again?

Solex Carb should in theory be the same on the 19TZS and TRS yet with the exception of that metallic cylinfder underneath the TRS does not show that screw attachment.

As far as I can tell its attached to a rood heading to the throttle assembly so am I correct to assume some knd of Choke?

velosolex50 · Post by **velosolex50** » Sun Apr 19, 2009 9:44 pm

Odd looking thing. I don't remember there being anything quite like that on my 1987 uk spec19 trs, although the rest of the carb looks fairly familiar. Possibly something to slow down the throttle butterfly rate of closing on lifting off? quite a few other cars have those. Probably emission related anyway. I will have a look in my french manual........don't speak very good french though, so don't hold your breath..........
Huw

velosolex50 · Post by **velosolex50** » Sun Apr 19, 2009 10:12 pm

Sorry, no luck in Haynes or the french one. Best guess is either a throttle butterfly damper as mentioned above, or possibly an enrichment device on wide throttle openings. Sorry can't really help.
(I was really glad my 'new' bx was fuel injected, I had spent hours failing to sort out the TRS carb properly).

kiwi · Post by **kiwi** » Mon Apr 20, 2009 1:44 am

Of the three BXs I have had in New Zealand 19TZS,19TRS,16RS only the 19s have had the cylinder with the three pipes coming out of it that I am lead to believe is some sort aireation device to stop fuel vapouring.

This screw fitting though I never noticed until getting this other 19TRS, thats what I dont understand what and why the TZS has yet another extra bit on the carb.

Could it be related in someway to the Aircon unit? Of the three BXs this is the only one with Aircon?

citronut · Post by **citronut** » Mon Apr 20, 2009 8:41 am

i think the unit under the battery tray is a vapour ventting device, and the canister with three pipes is a charcole filtter

regards malcolm

DLM · Post by **DLM** » Mon Apr 20, 2009 1:30 pm

I'd go along with something like that.

In Revue Technique there's no extra info but the carb-assembly the unknown sub-assembly's connected to is labelled "pompe de reprise" - recirculation pump is what I'd translate that as.

Similar to the device fitted to late petrols in the main fuel line?

kiwi · Post by **kiwi** » Mon Apr 20, 2009 9:57 pm

Its not the cylinder I am interested in that thing is on both the 19s I own, its that Screw type fitting with the pipe running from the crab to some sensor under the battery tray and back up to the screw fitting.

Others have suggested something to do with it being an Air Con Model, which I guess limits me a bit for replies when not many UK spec Cars are not fitted with AC.

Who ever said the BX is a boring car and all the same is very wrong indeed

DLM · Post by **DLM** » Mon Apr 20, 2009 10:49 pm

I think most surviving aircon cars in the UK are turbodiesel or fuel-injected petrol models - and not many carb-fed models had the aircon option.

Perhaps the Aussiefrogs forum would have better experience of aircon-equipped carb-fed BXs, as more were specced that way - and more survive.

Way2go · Post by **Way2go** » Tue Apr 21, 2009 2:09 am

It's possibly the anti-stall device that operates when the Air-con cuts in when the engine is idling?

Post by **Tim Leech** » Tue Apr 21, 2009 9:09 am

The BX GT had a replacement engine out of a 19TRS with A/C but Im not sure what bits adam swopped from the GT and what bits he left on, I know it has and aircon sump though and theres a blocked of pipe on the carb? Can take piccies next time I go and visit it.

velosolex50 · Post by **velosolex50** » Tue Apr 21, 2009 12:03 pm

My late 19trs auto

had aircon and didn't have that bit on the carb. I reckon its emission related, the anti vapour theory also sounds good.

paul001 · Post by **paul001** » Thu Apr 23, 2009 9:48 pm

I believe it is a vacuum unit for the autochoke or a damper for the accelerator linkage It is definately vacuum operated and the screw will reduce/harden the vacuum up. A lot of early Volvo carbs have the same system as does the SAAB 99 turbo

the other hose you've arrowed looks like a vent system for the carburation I think if you follow it you might find it goes to the rocker box vent hose or to that charcoal canister as it looks like it forms part of the egr system

kiwi · Post by **kiwi** » Fri Apr 24, 2009 11:20 am

Nope its not vaccum related unless its a second device? The vacuum follows the same path as normal from the rear of the carb to the vacum attached to the distributer as per normal.

It has nothing to do with that Charcoal Canister which is feed direct from the fuel system in both the 1900 BX I own.

I arrowed the two pippes associated with theis fitment to clarify one (the one with the red stripe) comes off the carb and winds its way to the second picture under the Battery Tray which is a small device attached to twin wiring block. It then comes back to the screw fitted device! via the arrows.

I do follow the theory some sort of vaccum as the hoses contain no fuel unlike the three attached to the cannister.

Basically I dont want to tamper with it until I know what it is/does as the winter is coming and getting her to start is becoming a mission.

Its got me as to the exact purpose as yet no one else has been able to show me a similer set up or what it does. Just hoping someone can point me to a good resource on the internet to work this out its like this damn car was a prototype or something.

DLM · Post by **DLM** » Fri Apr 24, 2009 12:49 pm

The Czech BX club have a carb-application document which shows this carb for a BX19 with aircon as

Solex 32-34-Z1 PSA 427 (aircon)

EDIT Finally found my lost Haynes carb manual as well - useless as the proverbial chocolate teapot as usual as all it shows is the standard 19 carb.

The item circled in the first pic is the housing for the "part-load enrichment circuit" (including a diaphragm assembly) shown without any extra pipes.

"At idle and during light throttle operation, manifold vacuum draws the diaphragm back against spring pressure" etc..

Can post the pages if you want. There must be a set of official BX manual pages for the extra setup - as was usually the case for a specialised system. I think that's the only possible documentation you'll ever find - apart from anything still in the head of a mechanic who worked on those aircon cars (or similar Peugeot ones).

citronut · Post by **citronut** » Fri Apr 24, 2009 8:25 pm

the other theary i had is its an anti fload capsual, similar to that on a dersh, im sure the devise under the battery tray is a vent as it will have a gause at the end towards the left hand (UK N/S ) inner wing, i also do have a set of genuine BX manuals, i will sit down and wade through the if i get time over the weekend

regards malcolm