SU hose query

[Tony Mc]

Just noticed this pipe/hose attached to the front carb hanging down loose. Looks flared at the unconnected end as though it belongs somewhere. Could someone tell me what it is for and where it should connect to or is it an overflow?
Thanks in advance.

 

[uk66fastback]

I think it's the breather for the fuel chamber. One end goes on the outlet on the top of the part of the carb where the float is. It looks as if you have the screws already out. The outlet in the middle more or less of those ...
I think the other end connects on the back of the air filter box? Thre are two small outlets, one for each carb.

 

[MaximG]

If it’s attached to the back of the carb it’s the vacuum advance for the distributor.

 

[Tony Mc]

Thanks for the input chaps.
The hose is about 15" long so could reach either the airbox or distributor I suppose. Its origin is on the piccy just north of the bell housing.
Someone had nicked the airbox during delivery. Jonbills kindly swapped out my distributor to a ZX recently so I will have a nosey around the distributor.
If it should be connected at the distributor, could that be why the engine is misfiring/coughing over 2000rpm?
Regards

 

[Rob Gaskin]

It def. should be connected to the distributor so either connect it or block it off and check your ignition timing.

Check that your other hoses are connected correctly - you have a few on there - US car?

 

[Tony Mc]

Thanks Rob. A mate said "it shouldn't need that as it is electronic ignition" ?
Yes, it is a US car. There are various blocked off hoses and random unconnected wires which will need to be tidied up.
I could do with finding somewhere there that sells threaded bungs just to neaten the engine area up.

 

[uk66fastback]

Is it not this?

And it goes on the back of the air filter housing, note the two small inlets. What’s the other carb got on it, I’m guessing probably nothing. If someone stole the housing, maybe they took one of the tubes with it ...

 

[Rob Gaskin]

Is it not this?

And it goes on the back of the air filter housing, note the two small inlets. What’s the other carb got on it, I’m guessing probably nothing. If someone stole the housing, maybe they took one of the tubes with it ...

Is it not this?

And it goes on the back of the air filter housing, note the two small inlets. What’s the other carb got on it, I’m guessing probably nothing. If someone stole the housing, maybe they took one of the tubes with it ...

Have you been to Specsavers recently?

If you look back at the original picture the pipe is coming off the venturi area of the carb, across the carb and then up to the guys hand. The floatbowl vent is not connected to anything - but does need a pipe to take excess fuel away from the exhaust.

 

[Tony Mc]

Is it not this?

And it goes on the back of the air filter housing, note the two small inlets. What’s the other carb got on it, I’m guessing probably nothing. If someone stole the housing, maybe they took one of the tubes with it ...

No mate, as Rob said that nozzle on the float bowl has a drain hose which I took off before taking the photo.

 

[MaximG]

No mate, as Rob said that nozzle on the float bowl has a drain hose which I took off before taking the photo.

Just to say the one on the float brown is not a drain it’s a vent pipe.

 

[Rob Gaskin]

Just to say the one on the float brown is not a drain it’s a vent pipe.

Yes but if the 'needle valve' sticks open fuel will pour out of it (especially if the car has an electric fuel pump) - I can speak from experience. Quite alarming.

It will fill up the airfilter.

 

[uk66fastback]

Ah! I didn’t think the out of focus pipe in the foreground was the same bit as the one running left to right on the top of the carb ... I thought it was loose at both ends

 

[Mark N]

You should be able to identify it from the Emission Control System section of the relevant FSM here:

http://www.xenonzcar.com/s30/fsm.html