1.1c Fuel Line Restrictors + Weber ICH 34 carburettor

Hi Guys, I'm new here and I hope you can help.

I've played with plenty of cars over the years but am new to MK1 Golfs - I have a 1983 1.1C.

Can anybody tell me about the Restrictors in the return fuel line - how important are they, where can I get one ?

The original Solex had a fuel supply line from the pump and also a return line back to the tank. The car now has a Weber ICH 34 which only has the supply line, I have put a T-piece in to give it a return back to the tank but it seems to suffer from lack of fuel - it's much better if I ignore the return line and just run with the supply straight from the pump. This is OK but the fuel is under some pressure (at the float needle valve), but with the T-piece in I don't think there's enough pressure without the restrictor.

Does anyone have any experience of this or the ICH 34 that might help ?

Many Thanks

Andy

I think thats the carb i run on mine, which im having problems with myself!  the k&n filter threw a spanner in the works, was perfect before that. getting the mix right is tricky, smooth tickover means rough accelerating and smooth running means wont idol :dontknow:

but any way mine has a return line but im pretty sure there are no restrictions in the fuel line :?  theyre a funny thing to get right, the only problems mine has ever given me is fuel/carboaration!

just have a fiddle, with the standard filter it should run sweet when set up properly :wink:

Greg 8)

Thanks for the reply Greg.

The Weber ICH 34 is simplicity itself and about the only thing you can adjust is the idle mixture - this doesn't affect the mixture under normal driving conditions only at idle, so I'm not quite sure what you mean by 'set up'.

I have had a look at the Solex I took off and the outlet for the return pipe had a restrictor in it about 0.7mm - I have put a restrictor in the return pipe of the T-piece using a Weber jet of 0.7mm.

I think they are important, without one and with a T-piece for the return pipe then there is a possibility that insufficient fuel will get to the carburattor float chamber and it will run weak. Without a return line at all and just a direct pipe from the pump to the carburettor there is a possibility that fuel will be forced past the needle valve in the float chamber and that the fuel level in the float chamber will be too high and it will run rich.

Perhaps you should put one in ! or connect the pump directly to the carburettor and see if it's any better.

I would still be very interested to hear any further information anyone has about these restrictors, they are shown in the Haynes manual diagram but there is no reference in the text.

Many Thanks

Andy

That screw u are on about is the fuel screw :wink:  there is another sprung screw which adjusts the throttle tension for idol, its the fuel screw which determines how much fuel it is constantly fed, my greater air intake makes it run lean, back screw off to let in more fuel :wink:  so im sort of playing with the balance at the moment.

i now see what u have done with ur fuel lines, put a T piece in the line from the pump to the carb to relieve fuel preassure? mine isnt like that, it has an actual return from the carb, infact there is a three point splitter in there where some is returned to the pump - i think :?  ill check tmorow.

Greg 8)

Hello,

I have the same Weber on my 1.1 golf c. I blocked off the return pipe, and i have an inline filter between the main fuel line and the fuel pump. It?s strange as the output from the pump has a thinner connector than the actual carb. To overcome this i used a reducer and two different diameter fuel lines. I also have a k & n filter that i use in the summer, and i use the standard air box in the winter. When i change between them i do not have to change the mixture.

This works fine, and i have never had any fuel/carb problems. (touch wood!)

hope this helps James Flashman

Iv just found out that your right! my carb is back to the standard settings, it was running poo cos the exhaust was blowing badly at the manifold/downpipe, sweet as a nut now :wink:  im actually fabricating a hot air feed for my K&N at the moment out of sheet alli, welded and formed, so hopefully it will be ok through winter

Greg 8)

what was wrong with your solex before you took it out

Thegreg said

That screw u are on about is the fuel screw :wink:  there is another sprung screw which adjusts the throttle tension for idol, its the fuel screw which determines how much fuel it is constantly fed

Hello Greg,

Thanks for all your comments.

Firstly it seems we are talking about different carburettors as the ICH 34 has only a single fuel input pipe on the 1.1 engine and no output, so you are correct I have put a splitter in the input pipe.

I think the screws you are talking about are;

1 - The throttle stop screw - this adjusts the position of the throttle butterfly opening by adjusting the throttle cable.

2 - The other screw, which fits inside a small spring, is the idle mixture screw and only adjusts the mixture at idle, once the throttle is open above idle the 'progression holes' in the main carburettor venturi feed the fuel into the incoming airstream. The amount of fuel is controlled by the main jet inside the carburettor body - most Webers are 'fixed jet' and do not have a mixture control screw.

Best Wishes

Andy

tupac2makaveli71 said

what was wrong with your solex before you took it out

Hello tupac,

The Solex was in pretty poor shape leaking from a number of gaskets and a strong smell of petrol after starting, it would not idle and needed the choke fully out to start it !

However it was not great when the Weber was first fitted (hardly any points gap !) but is now running better than ever with new points, rotor arm, distributor cap and HT leads, no smell of petrol either.

The Weber 34 ICH is simplicity itself - which is why I like it  8).

Andy

JFlash said

Hello,

I have the same Weber on my 1.1 golf c. I blocked off the return pipe, and i have an inline filter between the main fuel line and the fuel pump. It?s strange as the output from the pump has a thinner connector than the actual carb.

Hello James,

You are correct, the pump output and the carburettor have different pipe sizes - I just made the flexible pipes fit !

One other question, we now have two 1.1s with this carburettor and they both suffer from a slight 'hiccup' when picking up the power after changing up or down at slow speed - have you noticed this ?

Many Thanks

Andy

Hi again Andy, that sounds right, my carb is also the IHC34… BUT was fitted in around 1993/4 so there may be slight differences to a new one. mine definately has a return. i didnt realise the screw only controlled fuel at idle, does that mean u have no control over fuel intake other than changing the jets?

about ur question have a fiddle with the choke maybe? mine can run like u described if its off too early :wink:  there is a funny thing with mine on that point too, maybe same with yours?? - if i let engine get upto temp and completely close choke it will run rough as a bears arse, but if its left a further 10 mins before i completely close it its absolutely fine :dontknow:   

Greg 8)

Thegreg said

i didnt realise the screw only controlled fuel at idle, does that mean u have no control over fuel intake other than changing the jets?

Hello Greg,

There may have been some differences - I have two ICH 34s both have input only - hence the questions about restrictors !

You are correct about the fuel/air mixture intake under running conditions - it's all in the jets. Either the Main jet which controls the fuel, or the Air corrector jet (which allows air into the fuel before it is introduced into the main airstream). I have the details for Golfs from Weber;

1.1
Main Jet 1.27mm
Air Corrector 1.8mm
Idle Jet 0.5mm
Emulsion Tube F56

1.3
Main Jet 1.25mm
Air Corrector 1.25mm
Idle Jet 0.45mm
Emulsion Tube F7

The jet sizes are stamped on them and visible (with a magnifying glass) once you have removed them from within the float chamber.

I may have misled you slightly - under normal running (above idle) the fuel is supplied from the idle hole AND the progression holes - so it is possible that the idle mixture screw will have a very small effect on the running mixture.

I have just looked at my Weber information again, with a new ICH 34 it shows a Y-piece (T-piece) with a restrictor included although it does not state a size. I think I have this on one of my 1.1 Golfs so it is obviously desirable with single input only carburettors.

Andy

Andy,

Before i had my cylinder head reconditioned (new valves & guides) i did not notice a hiccup at all. However after this i did start to notice a hesitation when changing down and flooring it. After a while it corrected itself tho.

But at the moment my golf is in bits again, reconditioning the cylinder head had put too much pressure on the bottom end which has led to oil blowing past the rings……  :roll:

It will probably start doing it again after i bolt it all back up, lol

Cheers James Flashman

JFlash said

It will probably start doing it again after i bolt it all back up, lol

James,

I'm sure it will all be fine - if not then the sooner you find out then the sooner it gets fixed !

Good Luck

Andy

MKone said

Can anybody tell me about the Restrictors in the return fuel line - how important are they, where can I get one ?

After some further research and help from Webcon I have managed to answer my own question.

The Weber ICH 34 comes with a fitting kit and that includes a Y-piece with a restrictor in the return fuel line - it's a proper Weber part 999 0898 which I have ordered from Webcon.

Thanks for all your help and responses - Solex 31 PIC For Sale soon !

Andy

couple of questions guys - iv just brought a 1.1 formel E and it has a solex 31 pict carb, im having to start it up with the choke out and running it out ( not fully ) for ages and never pushing it all the way in. also its abit lumpy when changing through gears at low speeds? it sound like some of your problems with the weber.??? any ideas what will help.

also i wanna get a weber 34 ich - but is it really any better than the solex, sound like the solex has more set up control.

also does the weber sound better? or produce more BHP….?

oh im running with a KandN like most lol

can any1 help

Hello Logic,

It doesn't sound like my Weber at all which is just about perfect !

But it does sound like the problems we've all had with the Solex when it gets old !! Sorry no idea what the 31 is, try measuring the inside diameter of the carburettor barrel where the air filter fits on - wouldn't be suprised if it's 31mm.

Don't get me wrong the Solex is a good carburettor, but it is complex for the application on the small Golfs and lt's generally less well understood in my opinion, and bits are harder to get.

The Weber by contrast is simplicity itself and so easy to sort out/set up - you won't regret it.

The Weber ICH 34 is a straight replacement for the Solex 31 PICT but be careful as the jets are different between 1.1s and 1.3s and I think the 1.3 barrel diameter is bigger. You will however need a couple of gaskets and an adaptor plate to fit it, if you can find a new one then this will all come with the kit - I bought mine second-hand from Ebay with all the bits and still on the manifold for about ?50. Not sure if they're still available new, but then they are ?150 - ?175.

As you might imagine I would recommend the Weber, both me and my son have it on our 1.1Cs.

Keep posting - I can help with more details/fitting tips if you want.

Andy

Hello again logic,

Try reading this thread in Small Block Engines - "What would you do" as well - link here http://www.vwgolfmk1.o…ms&file=viewtopic&t=14063

Andy

HI MKONE,

IV BEEN ON FASTRAODCARS.CO.UK WHO SUPPLY WEBER CARBS AND THEY HAVE IN STOCK NEW ( ALTHOUGH LIMITED STOCK ) OF THE 34 ICH, BUT ITS FOR A LANDROVER - I KNOW THE 34 ICH WAS USED ON THE DEFENDER RANGE FROM OTHER POSTS ON HERE AND EDITION 38, BUT IS IT THE SAME FITTMENT STILL? IM SURE THE JETS WILL NEED CHANGING?

ITS ONLY ?89 NEW. SOUNDS A STEAL TO ME.

http://www.fastroadcars.co.uk/store/view_product.php?product=15290.627

YOUR RIGHT, THE WEBER DOES SOUND A BETTER OPTION

Logic,

FastRoadCars are excellent, try ringing and asking them about jets and fitment to the Golf.

I have looked at the Land Rover carburettors in the past and I'm sure they will fit with a bit of effort. Certainly the fuel line input is in a slightly fifferent place and I don't know if it comes with the correct adaptor plate but a 34ICH is basically a 34ICH ! I also believe there are different venturi sizes for the different Golfs - this might be the 31 and 34 numbers on the Solex PICT 31/34 carburettors ?

If FastRoadCams can't help give Webcon a call, a chap there called Andy Gray is excellent.

Please post back what you find.

Andy