Carb overflowing?

Kitch · Post by **Kitch** » 19 Jul 2006, 20:14

Having just changed the carb on my AX GT, the car won't run! It starts and splutters, creates loads of smoke etc. Then dies. When it dies, fuel spills out the top of the carb! Not eithe rof the chokes, the two other ventricles downs the sides of it between the chokes. I know jack about carbs sadly, any ideas?

Thanks.

jeremy · Post by **jeremy** » 19 Jul 2006, 20:44

Sounds like the needle valve isn't shutting properly or the float has sunk or a link has jammed. (jamming could be because the carb has been turned over when off the car and something has caught.)

As a first (and scientific) I'd give it a smart tap with a block of wood to see if anything can be freed. If that makes no difference then its time to take off the top and have a look at the float and its chamber. You may need a new gasket for the top of the float chamber.

I assume that the thing has an engine driven fuel pump and hasn't been converted from injection or something. I mention this as the output from a mechanical pump on the engine is usually around 2 or 3 psi, proper Bosch fuel injection electric pumps are 36 Psi and I think the throttle body injection pumps are about 8 psi. Anything other than the mechanical pump may overcome the needle valve.

sub42 · Post by **sub42** » 19 Jul 2006, 20:54

Is is the solex carb?

AndersDK · Post by **AndersDK** » 19 Jul 2006, 21:48

http://www.rwbsmith.plus.com/citroen2/Carburation/

Thats pretty much all about carbs on AX/BX 8)

James.UK · Post by **James.UK** » 21 Jul 2006, 01:12

Hmm it's been a while since I played with a carb!! But from memory - - -

Basicaly the float chamber on a simple carb works like a ballcock. When the petrol comes into the float chamber the float rises untill it shuts a valve and prevents any more fuel entering.. When fuel is used the float falls and allows more fuel to enter..

Faults can be -- stuck float... Punctured float... dirt in the valve preventing closure.. Or the float is badly set so that it allows too much fuel in before it closes the valve..

Now if I can just suss out how to fit twin SU's to my ZX it may develope just a small sense of urgency huh?? lmho...

citronut · Post by **citronut** » 21 Jul 2006, 08:34

where did the carb you fitted come from and how long had it been sitting around,it probably just needs the top removing and a good clean out/b**w j*b,then check and set the float levels before refitting the top,also why did you change the carb
regards malcolm