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Conference terri::cars_uk

Title:	Cars in the UK
Notice:	Please read new conference charter 1.70
Moderator:	COMICS::SHELLEYELD

Created:	Sun Mar 06 1994
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	2584
Total number of notes:	63384

1725.0. "Help required on VISA plumbing!" by ROCKS::KEANE () Thu Mar 12 1992 12:25

    
    Hi,
    
    I would appreciate some help from you gurus|
    
    I am restoring to running order an old Citreon VISA fitted with the two
    cylinder 652CC horizontal engine.
    
    I know its tat, but it was a cheap car and there is no rust in it!
    
    However some of the plumbing is missing, and I am not sure where to
    connect it.
    
    If anyone has one of these beasts, and could identify a pipe connection
    I would be very grateful.
    
    Failing this I would appreciate some ideas from you armchair experts!
    
    The problem are is:-
    
    The air cleaner has two inlet ducts, one for cold air, the other, hot air
    from the exhaust manifold. The hot air duct is controlled by a hinged
    flap that is operated by a VACUUM bellows. There is a short 4mm stub
    pipe to connect to a missing flexible pipe that goes somewhere  Where?
    
    I assume that the connection must be somewhere on the carburettor or
    inlet manifold in an area of high depression, but I cant find a take
    off.
    
    I do not understand the use of this mixing system fully. I can
    understand it when the engine is cold, the choke is on, the flap is
    open and after a couple of minutes, hot air from the manifold will be
    drawnm into the engine, stopping any icing and assisting with emulsion
    of the mixture. However, I assume that the flap will also operate on
    over-run, when the butterflies in the venturi are closed. (twin choke
    carb.).  Does this matter? Why?, whats going on?
    
    Perhaps the Visa never used this system, and its a left over from some
    other model?
    
    If I dont connect it, is it going to make any diference to the long
    term ecconomy, or the "emission control" for the new CO2 regs?
    
    
    Any advice gratefully received.
    
    Pat Keane  830 - 3839   Rocks::keane

T.R	Title	User	Personal Name	Date	Lines
1725.1		PLAYER::BROWNL	Assume the 'on-tow' position...	`Thu Mar 12 1992 12:30`	5
	Speaking personally, I wouldn't give one of these, or any Citroen for that matter, scrap-yard space. So, I can't help beyond saying "Buy a Haynes manual!" Laurie.
1725.2	Haynes is no help!	ROCKS::KEANE		`Thu Mar 12 1992 13:38`	15
	Thank you Laurie for your kind advice! I did invest in a Haynes manual for the Visa. Haynes, in their inimatble manner have one photograph of the engine bay, obviously taken with a box brownie, that has had a greasy thumb applied to the lens. It is impossible to make out any detail of the engine let alone any details of the plumbing! Still require pertinent advice and not put downs! rdgs Pat K.
1725.3		AEOEN2::MATTHEWS	In a negative brownie-point situation ...	`Thu Mar 12 1992 13:50`	6
	Are you sure it is vacuum operated ??? I would have thought it would be controlled by outside temperature, and hence some sort of thermostat. I have a system on my BM which takes air either directly from the outside world, or the air passing through the radiator. There is a thermostat which switches between the two air flows (mechanical only).
1725.4	2CV is like this....	CURRNT::RAMSAY		`Thu Mar 12 1992 14:08`	8
	Pat, if the 2CV system is anything to go by, there are two pipes (one each side) which come from the inner wing panel to the box, a flap valve in the box directs the hot/cold air through the 'other' two pipes to the interior of the car. As the Visa is a rebodied 2CV in effect, this could still be the case? NR
1725.5	Sure it's original spec?	TIMMII::RDAVIES	An expert Amateur	`Thu Mar 12 1992 15:53`	18
	Replying to pat (who's about two cubes away as the crow flies, me lazy?, never) Yes it takes the vacuum from the manifold, purely to use a a motive force. Internally it's got a heat sensing valve that switches the vacuum to the flap that switches between the two air inlets. I've got a similar system in my AX (why junk proven technology) Re the overrun.... this is irrelevant, the sensing is inside the air intake, the vaccuum is only motive fore. Re does it make much difference?. My old 4cyl visa used to have a manual flap, set it to warm air for winter, set it to cold air for summer. None of this sophisticated sensing. Richard
1725.6		PLAYER::BROWNL	Nubile Arrow	`Thu Mar 12 1992 16:07`	3
	How about a visit to a scrap yard? Laurie.
1725.7	Been there done that!	ROCKS::KEANE		`Thu Mar 12 1992 16:23`	4
	Thats where I got it from! 8>)) pat
1725.8	Call garage.	IRNBRU::WILSON		`Fri Mar 13 1992 16:28`	12
	Pat, I'd give my local Citroen garage a call, and ask to speak to the service manager, rather than second guess! Anytime I have queries on my Audi, the local VAG garage is very helpful indeed......as are most nowadays. John.