Water hose on (automatic choke function) carburettor Mystery

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Turboalternator
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Water hose on (automatic choke function) carburettor Mystery

Post by Turboalternator »

Hallo all,

I am wondering if anyone has some definite knowledge on this:

I recently fitted a new carburettor and had to dismantle from the old and refit to the new a water hose that goes from the rear of the carb to the front of the carb. From this hose the water then passes through the thermostat module of the carburettor which controls the automatic choke strangler butterfly.

What I discovered was that this pipe appears to have a restriction built into it to limit the flow of water.

I have pretty well convinced myself that this restriction is a designed feature but I cannot find anyone at Citroen who will confirm it.

The point is this: If the restriction is deliberate then the idea might be to prevent the choke opening too quickly and a cold engine running lean and hot and thus leading to possible damage.

If on the other hand it isn't and I just have a blocked hose then my carburettor is taking too long to open the choke fully and thus will not be helping to achieve low fuel consumption.

I have tried very hard to unblock but it just feels like a rubber constriction.

So if anyone knows for sure can you post please? Anders?

Best regards to all.
19 TRS Estate
In the past: 2CV, Dyane 4, GSA
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DLM
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Post by DLM »

Can't advise on this, but if you're after advice from Anders, he's to be found more often nowadays on the French Car Forum: http://www.frenchcarforum.co.uk/
Back on two wheels and pedal power for the moment.
Turboalternator
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Carburettor mystery

Post by Turboalternator »

Hallo David!

Very nice to hear from you and thanks for the tip. But I would also welcome anybody's input - wild, crazy or whatever!

I realise that most members appear to have diesels, but still.

All the best
19 TRS Estate
In the past: 2CV, Dyane 4, GSA
Be faithful to your BX and she'll be faithful back
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DLM
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Posts: 1620
Joined: Mon May 16, 2005 6:41 pm
Location: Gosport, Hampshire, UK
My Cars: Historically, lots of BX hatches/estates in the 90s/00s - 16/19i/17td/19d
Recent scruffy diesel n/a estate - "The Red Shed" - is no longer mine.
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Post by DLM »

I started off my BX ownership with a couple of BX petrols (16RS), but left the carb area well alone. Even when I did find a carb a with manual choke conversion in a scrapyard, I never got round to fitting it.... nor indeed did Kitch I think, who I passed it onto.

If I remember correctly, the coolant feed to the autochoke is the highest point in the coolant system on a carb-fed BX, which is one of a number of potential reasons for the thing not working as it should.
Back on two wheels and pedal power for the moment.
kiwi
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Re: Carburettor mystery

Post by kiwi »

Turboalternator wrote:Hallo David!

Very nice to hear from you and thanks for the tip. But I would also welcome anybody's input - wild, crazy or whatever!

I realise that most members appear to have diesels, but still.

All the best
I got two petrol BXs :D

Until now have not replied because I dont have anything to input, however I am interested in finding out a bit more on you dilemma as one of my 19TRS has a problem with cold starting/short running and there is potential for this to be a reason for that as well.
1991 BX19 TZS 04/01/91 (Deceased)
1990 BX19 TRS 27/10/89 (Reborn)
1992 BX19 TXD (Ex UK - K 744 SDF) 15/06/92
1990 BX19 TZS Auto 06/11/1989
1992 BX TZD Turbo Estate (Ex UK) 1/07/91
Turboalternator
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Highest point

Post by Turboalternator »

Hallo David,

The highest point in the cooling circuit is a very, very interesting point. It may hold the key to what I am trying to find out. Let me know what you think of this analysis:

Certainly, I believe, that that highest point would be a spot where an air bubble, (air lock), would form when the engine is switched off and the engine cools down. (easy to check: disconnect pipe when engine is cold and see if any water is present).

The question that then arises is what happens when the car is started again.

Does the air lock disappear or does it persist, only slowly disappearing, and , consequently, hinder coolant flow? Does a restricted pipe, somehow, help in getting rid of the air lock?

Alternatively or/and additionally, and again because the carb module is at the highest point in the coolant flow circuit, would a restricted pipe be useful in reducing back flow when the engine thermostat opens, thus starving, (or reducing pressure), coolant flow to the carb?
19 TRS Estate
In the past: 2CV, Dyane 4, GSA
Be faithful to your BX and she'll be faithful back
Turboalternator
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Posts: 82
Joined: Tue Apr 28, 2009 7:22 pm

Post by Turboalternator »

Kiwi wrote:

"...as one of my 19TRS has a problem with cold starting/short running and there is potential for this to be a reason for that as well."

Hallo Kiwi,

I'm not sure I understand what you mean by "cold starting" and "short running" can you explain please?

Also sometimes you can damage a pipe whilst trying to get it off .. So I'm not keen to encourage you to do that .. but having said that I would love to know if your pipe also seems to be partially blocked!

Thanks,[/quote]
19 TRS Estate
In the past: 2CV, Dyane 4, GSA
Be faithful to your BX and she'll be faithful back
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