Weber carb - fuel vapour seperator question..

Right. 1st up i'm not usually a numpty n usually sort theses things out easily myself BUUUUUTTTT on this occasion….  

My 1.8 Clipper had a new weber fitted when i got it n was running like poop so i started investigating and posted on here a few times trying to get it sorted.

Parts fitted n work done - new base gasket, carb overhauled cleaned, checked blown (and new was confirmed!), new fuel lines in engine bay, timing checked over, new plugs n leads, new fuel pump (this was def dead or dying!) tank sender/pick up was removed n cleaned, front to rear hoses blown thru, new fuel filter and a new fuel vapour seperator fitted!!

Then when i drove it there was still a fuel starvation problem where it kept breaking down all the way to work this mornin!!! gggggggrrrr! :evil:

SO after another check over everything I removed the fuel vapour seperator!!! SUCCESS!! She drives beautifully now!!

My question is should i have removed this?? The Weber has no return hose but the floats in the carb close off when theres too much fuel anyway and keeps pressure in the fuel line so i can't see i'm flooding the engine with fuel and there was loads of fuel returning thru the seperator so am I correct in thinking they should be removed when a Weber is fitted?  :?

And I have plugged the return hose just in case before anyone says that..!

Get a new one on, your only asking for dirt crap etc to go direct to your carb thus eliminating the work you already have done so far plus the vapour separator has a job.
Your original one would have been full of rust etc thus the cut outs, simply buy a new replacement and job sorted
Pete :wink:

It was a BRAND SPANKING new one, n'other ?30 wasted!!  

Speaking to other bods in the trade from my T25 van stuff and they reckon that seperators don't work very well on Webers due to the fact that a weber fills and cuts off via the float valves in the carb hence no return fitted to the carbs. I have renewed, rebuilt or checked EVERY part on this cars fueling system and since removing it she runs perfect. (and yes the pipes were connected the right way round!)

The clear disposable fuel filter stops 99% of crud so the seperator is in the way as far as I can see! Do you run your Weber thru the seperator OK then Pedders, got to respect your opinion I know you're more up with these than me!!  

Jus interested to see that there are lots of Weber fuel starvation type posts on here and I wonder if it proves to be the problem with mine then maybe it could be a way around it?  :?

i have similar issues on my weber 1.6 carb auto - fuel starvation at low revs.

i also swapped seperator, fuel pump, filter, cleaned tank pick up carb etc and came to a blank

it has gone to the best carb tuner in the area for a rolling road tune / set up so i will post up any findings he makes.
 i thought about bypassing but was concerned about any back pressure and what it would do ( petrol over hot engine if back pressure blows a weak spot )

Always since having vw's have fitted a new weber, always replaced everything with new, carb flange, separator etc and mine purrs fella, just been to wolfsburg in mine, and germany and poland last year in her and not a missed beat.
So your problem is lying elsewhere.
I have 32/34dtml carbs always, what weber have you fitted, and i hope you haven't been stripping it breaking gasket seals on the carb?

For a living i restore and rebuild Vw T25 vans to pretty high standards ( http://www.brick-yard.co.uk/forum/peetz-projectzzz-finished_topic32381.html ) so am well versed in carb rebuilds and def didn't break any seals and yesterday was the first and last time i shall look inside it for the problem!!    

The vapour seperators aren't fitted to many T25's (only later 1.9s) and they are usually removed due to lengths of pipes etc causing fuel starving probs - it's what i've known them for before.
It just doesnt' make sense that the car runs perfect without it - i have checkd n rechecked the hoses are fitted the right way round etc btw! - it drove me nuts - the car was bought for fun and has been a bigger pain in the harris than all but one of my customers vans so far…  

Then again it runs sweet as it did yesterday n a grin returns!

Pedders what do you think the seperators are actually for anyway as I really can't remember since we usually jus chuck em away being as pains in the harris!!  :dontknow:

I just wonder how many of the fuel starvation probs which seem to be posted on here can attributed to these things?
BTW the new one was from GSF which isnt well known for its quality dya reckon a pukka Vw one could be the solution, is that what yours is?

first fault found in the carb …

float chamber was over filling so flooding the manifold on startup, all rest of carb appears clean and ok.

onto the rollers next for timing and mixture………

Like i say peet, the problem might be lying elsewhere.
I am not saying you do not know nothing, going by your question " do you know what a separator does" which to me seem'd like a sarcastic reply
It separates the air and/or vapor from the fuel and provides basically  air/vapor-free fuel for use by an engine and returns the filtered air/vapor and any excess fuel to the vehicle's fuel tank.
I am here to help, but it would be better hands on the car, your limited to info over the net as you know lol
Mine is a VW separator as it was goin for a song on ebay, thou my 1.5 x reg had a plastic black one as standard from factory, this is where i found the issue with these.
My gl would not run right period after changing everything new when i bought it inc filler neck, lines etc etc.
I come to the separator and disconnected lines to it, tap'd  it in my hand and it was full of rust particles.
Bought one from gsf fitted and car run smooth and never spluttered i.e. no signs of fuel starvation.
But you say the car runs well without, so obviously has to be the the separator blocked.
I have had approx 5 cars with this type of engine inc mk2 golf and scirocco over past 17year and everyone i have had purring after replacing all parts for new, as i not one for buying a car and simply drive it, everything is replaced with new, as these engine are the most simplist block made, the fuel setup is very easy to overcome and maintain along with the eletrical setup.
Like i say easier when hands on bud, can you say excactly as regards fuel setup you have done to it?
If you are close to me would be better
Pete

Sorry Pedders def not meant in a sarcastic any way at all, trouble with text n writing sometimes what I mean goes awry - i'm the one asking for help get me head around this here!!!  

So it still doesn't make sense to me as I have replaced every part for new, i checked the seperator today nowt in there cept fuel and blown out with the air-line again. The only part I havent replaced is the fuel filler pipes but again I have blown these thru and checked in the tank for debris again nothing..!  :dontknow:     

So if carbs fine, pumps replaced, lines replaced or checked etc any idea where i should try next please?

So carb flange replaced? can you do me a favour, a few pics of bay please, inc fuel/vac lines, might be something i could possibily spot, seem wierd you have a new separator and it continues when removed?
Weber is defo new? i.e in terms of looks new or you have recipet of proof new and it hasnt just been cleaned?

List n order of job done..

new vw flange
new in line fuel filter
new seperator
new fuel pump
new hoses in engine bay
new fuel cap
ignition timing checked
carb stripped down cleaned no crap in there at all n rebuilt - it is brand new, no receipt but it's def not jus a cleaned up carb and it is as it should be and is still runnin perfectly but now with no seperator.
rear sender removed and cleaned - it wasn't dirty anyway.
both front to rear pipes blown thru with the airline.
rear filler pipes checked over and OK
fuel tank had very minor sediment but tiny amount.

When it cut out I could see no fuel in the inline filter then it pressurised itself and would run again.

The last possibility I can see is that the pipes on the seperator where the wrong way around but they are the same way as in your piccy too - I have had a few fuel pumps from GSF where they were marked up/made wrong so maybe I shall try lookin at that?  :dontknow:

 I'll take a piccy next week.

Thanx for your help Pedders!

Sounds like theres no restrictor in the return line to me, but im not certain theyre fitted to these anyway- maybe with the pierburg they were and this is why the webers playing up?
If the fuel line to the tank isnt metered back the fuel pump will simply pump the fuel from the tank, to the separator and back mostly down the return.
You really need to check theres 3 or 4 psi at the carb when its running otherwise itll starve the carb every so often and cut out.

Just a thought….

There's nothing in the return line at the front end an indeed I can see the fuel being pumped straight back down the pipe back to the tank as quickly as its being pumped up!  8O

Where does the restritor sit? It makes sense if it isn't there and it would also make sense with all the problems i have had with the car since i had it!
Found out the previous owner fitted the carb new as he had the problem n thought it was the carb and he still couldnt get it to run right which must be why i got it at a bargain price then!!  

Things you find out after you buy something eh? - sure there was no mention of that in the e-bay advert..!  

Thanx for the help chaps!

Weber used to supply a "T" made from white nylon in their carb kits that went in the line to create that restriction for the return, thats why youve not got one if you got the carb off the bay.

Youll likely be able to get one from a weber dealer as theyre pretty common still.
From what i recall it was simply a jet of a certain size screwed into one side of the T which went straight into the return line.

Overboost said

Weber used to supply a "T" made from white nylon in their carb kits that went in the line to create that restriction for the return, thats why youve not got one if you got the carb off the bay.

Youll likely be able to get one from a weber dealer as theyre pretty common still.
From what i recall it was simply a jet of a certain size screwed into one side of the T which went straight into the return line.

I haven't got mine fitted…

Would that suggest why at low revs it splutters a touch?

1.5 GL

Car was from the bay not the Carb but i know a weber dealer so will ring him! HOPEFULLY that was what was missin all along then!!  

http://www.clubgti.com/forum/showthread.php?t=86726

this page shows the fitting instructions - no mention of a T piece.

it talks about fitting fuel supply from seperator. the mystery continues….

I used to fit these carb kits on a daily basis and most all of them had the nylon "T" piece in the kits.

The clue here is that it runs fine when he plumbs the fuel line straight to the carb, but when he utilises the separator its diverting fuel down the return line instead of to the carb.
Remember, diapraghm mechanical pumps dont produce much in the way of pressure.
Since the pumps been replaced we can likely rule it out of the mix, so if its running fine when its plumbed direct, it has to be that the fuel is being mostly diverted away from the carb and starving it under driving conditions.
Only way to prevent that using the components he's got is to install a restrictor in the return and cause the fuel to fill the float chamber.

Unless theres a glaring error here?

Havent located one yet BUT it is still runnin perfect without the seperator! Will get one its on the to do list now...

Overboost said

I used to fit these carb kits on a daily basis and most all of them had the nylon "T" piece in the kits.

The clue here is that it runs fine when he plumbs the fuel line straight to the carb, but when he utilises the separator its diverting fuel down the return line instead of to the carb.
Remember, diapraghm mechanical pumps dont produce much in the way of pressure.
Since the pumps been replaced we can likely rule it out of the mix, so if its running fine when its plumbed direct, it has to be that the fuel is being mostly diverted away from the carb and starving it under driving conditions.
Only way to prevent that using the components he's got is to install a restrictor in the return and cause the fuel to fill the float chamber.

Unless theres a glaring error here?

I've got my T-piece sitting here.

White plastic, with a brass color screw in the end.

But its got a hole in the little brass thingy, is it supposed to have this hole?

Edit: After a test it seems that this T-piece is supposed to totally replace the vap separator?

Free flowing ends go from fuel pump to carb and the restricted bottom of the 'T' is the return?

Am I correct?

Edit: BTW sorry for coming into your thread!