Where's My Fuel Going?

[Guest mkeats02]

why is my carb dumping its fuel into my engine after the power is cut, anti run valve is working but the float in the carb dissappears why?

 

mike

[Bob Tucker]

What Carb??

[Peter Bell]

What do you mean by

but the float in the carb dissappears

Paul Daniels? do you mean fuel in the float chamber? it will slowly evaporate but unless there is a hole in the chamber it won't happen quickly. Can you see it coming out?

Peter

[Guest micky bigthumbs]

leak in the diagframe

[Guest mkeats02]

hello

 

it is a dfth carb, definitely not evaporating, was far too cold yesterday, and dissappeared too quick, it sounded like the fuel was just pouring into the engine.

 

any more ideas?

 

cheers

 

mike

[Guest mkeats02]

does anyone know what to suggest?

 

mike

[Bob Tucker]

Mike,

if the needle valve is knackered/stuck/not working, there is still pressure in the fuel pipe after you switch off. the level in the float chamber could then go up & spill into the throat. I assume you're using the mechanical fuelpump?

 

Bit stumped for any other ideas....can you borrow a spare carb & strip & refurbish yours?

[Guest mkeats02]

thanks

 

will take my carb off and have a look at it, may have to take it somewhere if the refurb job looks a bit daunting. luckily the car isn't on the road yet, got a few more jobs to finish off first before the SVA, got a meet at the weekend, will be able to pick more brains then, will remove the carb on sat and have a look

 

mike

[Peter Bell]

Mike does it really empty the float chamber or do you just get a little squirt from a jet at the top of the carb when the engine stops? If it is the latter it may be the 'love' valve (low vacuum enrichment) I think the DFTH has one? dumping its contents as there is no vacuum left to hold it. The only way the fuel in the float chamber can get out is by being 'sucked' by the venturi when the engine is running, a hole in the bottom of the float chamber, or some strange siphoning effect. As Bob suggested if the needle valve is leaking then it could overfill but it would be doing it all the time the engine is running and leaking everywhere and running very rich. Does it run ok the rest of the time?

Peter

[Andy Spencer]

Mike

I have just taken my 1600 engine out of my car. On it was a new 28/30 DFTH twin choke weber that I got off ebay, its done 1000 miles or so only, 6 months old.

PM me if you want it, I am sure we can come to some arrangement.

 

Andy

[Longboarder]

Does your DFTH have a stepper motor on it? If it does it goes through about a four second throttle opening cycle after you switch off which could activate the acceleration pump if it's not properly adjusted and give a squirt of fuel down the choke but only a couple of cc's.

 

Nigel

[Guest mkeats02]

when i tried the engine again, it would turn but not fire, i switched it off, the trickling noise continued, it was far worse if i disconnected the anti-diesel valve, which indicates to me the valve was working. It seems like there is a leek there but what would cause it. I don't the think DFTH carb on the 1600 does have a stepper motor, but I may be wrong.

 

Mike

[Guest art b]

Mike

I have just taken my 1600 engine out of my car. On it was a new 28/30 DFTH twin choke weber that I got off ebay, its done 1000 miles or so only, 6 months old.

PM me if you want it, I am sure we can come to some arrangement.

 

Andy

hi andy i saw ya engine on ebay,

i like the expansion tank set up,ive not seen that b4 where do ya get the hose with the small take off pipe?,

good luck with the engine sale,

ive got a 1.6in my garage too,got a 2.1 to go in, what engine are you putting in yours?

[Andy Spencer]

All

Sorry for any confusion - I have not listed my engine on ebay, I took it out because I wanted to upgrade to 2 litre and the 1.6 was getting tired (needed new rings specifically). Any that you see on ebay are NTDWM I'm afraid!

 

The purpose of the post was to offer Mike the good, virtually new carb off my cream crackered engine, which we have now sorted by PM.

 

Andy