A laugh, a song, and a Citroen BX - Tim Allcott
Just to prove the power of suggestion, I bought a 1990 Citroen BX
TZS automatic estate on Friday. 120k miles, full main dealer history to 100k (probably nothing since then) M.O.T. to May, taxed'til April. (300 UKP yes, I know I was robbed, but...) I do like to give fellow readers a quiet smile as they surf with their cup of tea!
I think the automatic choke is sticking on, as after a happy start, as the engine gets warmer, it loses power until it stalls altogether. Initially it drove well (on the test drive, and on Friday) so it's an intermittent fault. I know it could be other things, but I've convinced myself this is it.
Easy fix, or down to the local carb specialist?
Vehicle is otherwise straight and tidy, but needs 4 new tyres.
Some people really do seem to treat cars as disposable items...
Re: A laugh, a song, and a Citroen BX - Darcy Kitchin
I think you can easily see the choke flap if you remove the air filter to carb pipe. IIRC the choke flap works on one throat of the carb. That should prove your diagnosis; what to do about it only the experts can say.

Good luck.
Re: A laugh, a song, and a Citroen BX - ChrisR
Well done for taking the plunge. For 300 quid you can't really go far wrong. Or can you? Find yourself a good independent Citroen specialist and get him to service it and look it over for you. Don't know who that would be in Hull, but somebody on here might. They are marvellous cars, even at this age, as long as you keep an eye on them. I bought one in April, and after a troublesome start (caused by neglect), it's been brilliant for the last 10K miles. I don't know any more how people manage with coil springs.

This link has a good section on things to look out for (better than Haynes):


Sorry I can't help with the problem - mine's a diesel.

Re: A laugh, a song, and a Citroen BX - David M
Congratulations on taking the plunge, Tim, there should be life in the old beast yet....

While the carbs on BXs can be troublesome, give poor fuel economy, and cause high fuel consumption, they shouldn't stop the engine. A quick look at the plugs should give ample evidence of any excess carbon indicating sticky autochoke (very likely - manual choke conversion about £50 + fitting).

However, one item that is often seen missing on old carb BXs is the flexible "concertina" pipe leading from air intake to a point over the exhaust manifold (or vice versa, if you think of the airflow). This ensures a ready supply of warmed air in cool weather which stops carb icing, which sounds more like what you're suffering from.

If this "concertina" pipe is missing, you should be able to fix it with a trip to the local auto shop for a suitable length of tubing and a couple of clips to hold it in place.

For other info and questions, you should find links on the DIY site mentioned below - try the BX technical forum.
Re: A laugh, a song, and a Citroen BX - David W
Was this to replace the old 7 series Tim?

Have you got the twin choke carb with the waxstat auto-choke capsule that sticks forward on the left side as you look at the engine?

It is very common for this waxstat to get air locked and then fail to bring the choke off. It is at the highest point on the cooling system.

On my 1988 BX19TRS this became so much of a nuisance I fitted a manual conversion kit to great success. Having said that the BX auto-choke is one of the better systems...as long as it is correctly set up exactly per the manual and then not fiddled with.

What can happen is that it air locks then someone who doesn'k know this tries to sort it on the linkage, result a right mess.

Feel free to ask more specific questions of mail me off-forum if it's going to get very detailed.

David Woollard
BX Section
Citroen Car Club
Re: A laugh, a song, and a Citroen BX - Tim Allcott
Thanks to all who replied, particularly 'the Davids'
Yes, the concertina pipe is missing, and I will replace it tonight.
As for the 'waxstat' (David W.) I will do some homework with the Haynes manual tonight, from memory, though, there is a 'black box' to the left hand side of the carb as you look at the engine
About casette size. Does that provide any clues?
Apologies to all readers for being so specific, and, should I need to converse with particular people I will do so 'out of forum'.
I'm looking forward to this, having only covered 10 miles so far!
and yes, David, it did replace the BMW 7 which went for parts to a good home.
I feel like I'm at an AA meeting here... my name is Tim, and I get oily fingers from old cars
Interesting thought, though. I only need to do 8 miles a day, bits and bobs at weekends, there is a bus alternative, so my motoring really can be a hobby, and I can run all sorts of bizarre trivia (not to indicate that a BX is such) Wartburg anyone?
Re: A laugh, a song, and a Citroen BX - David W

You might be interested to hear that, through the CCC, I have tabs on a one retired owner BX 16TRS Auto with a genuine 27,000mls, full history and £1000 (yes really) spent in the past year.

OK I know what we all say about short run cars but if you were looking for one to preserve for the future this is the type of background that gives a vehicle real credibility.

I think the black box you refer to will be the choke linkage cover. The waxstat sticks from the front of that area with one hose going to the thermostat area and another to the rear of the carb to a "hotspot".

You need to check there is a coolant flow in both directions through these pipes and bleed them to ensure correct choke opertaion.

Bleeding the BX is something of an art and needs to be done with a header tank arrangement. I have just covered this in a recent CCC article and can mail you details if you want.

There are many other things that can cause your type of problem but you need to get any possible choke malfunction sorted as it will be crucial to your short runs.

In fact it was similar short runs and the crippling fuel consumption under these circumstances that made me seek the manual conversion.


Value my car