Fuel starvation weber carb

[G5 VWS]

Ok here goes.

I've finally got my gt11 back on the road today. The fuel filler neck had more or less snapped in two and let all manner or rusty in my tank and up through the fuel system making the car ran like a bag of nails and cutting out.

So I went about fixing the issue working from the back to the front

Parts replaced are as follows.

New rust free filler neck

Tank out and cleaned

New metal fuel lines

New rubber fuel lines

New in line filter

New pump

New swirl pot/ vapour trap

New rubber carb base

New weber carb

So to the problem. The car is running great under normal driving conditions through town and on longer runs, but when I give it full throttle the car coughs splutters and loses power as if it's starving of fuel. If I back off a bit it's fine and continues to drive normally. Really annoyed after spending so much time replacing parts. I by no means drive foot to the floor all the time only when dropping a gear to overtake or if the mood takes me on the odd occasion

Any thoughts or suggestions greatly received

[Nate]

Check filter clear, check pickup clear, check inlet filter on carb clear, try blocking or at least restricting the return

[Risocco]

try blocking or at least restricting the return

This.

I used to have to bypass the swirl pot - hose direct from fuel pump to carb. Car never cut out again.

[G5 VWS]

Thanks folks

I'll try restricting the return in the morning and report back. What's the best way to restrict it?

I'll stick a new filter on for good measure

[Nate]

Depends what sort of pipe its made from. You could try just folding it in half a putting a cable tie round it

[bengould]

Hi,

I've removed the swirl pot and replaced with a plastic y adaptor. To restrict the return I used a welding tip just screwed into the adapter. I think I've got a .6 or .8 in mine and it works fine.

Ben.

[G5 VWS]

Issue resolved

I put a .8 welding tip in the return pipe just after the swirl pot and now I can use the full rev range up to the red line no issues

Thanks for all the help.

[daffy.dub]

I have exactly the same problem, everything has been replaced. I've got a brand new Weber carb and its just been tuned, hydro carbs are 182. The car runs brilliantly until I bury the pedal into the carpet, either overtaking or accelerating up a hill. Whenever I do this it hesitates then picks up, feels like fuel starvation.
My dumb question is, what's a welding tip? and where do I insert it assuming my problem is this swirl pot? Or how do I bypass it?
Cheers.

[MacColl]

Green arrow points towards Y connector replacing swirl pot/fuel vapour separator which can be bought at Halfords (two in a pack).

Red arrow is where the brass/copper welding tip is hidden. These tend to be 0.6 or 0.8mm holed for welding wire that have a thread to attach to the end of mig welder. The thread can be simply screwed on to the end of the plastic pipe under that fuel clip. I drilled the little hole slightly bigger to about 1mm to allow for slightly less restriction.


Finally my general advice for a lot of these fuel issues/cutting out etc etc.. is check and probably replace the filler neck (check for inner corrosion), rubber connector, Fuel tank (mine is rotten at inlet flange, never noticed for months) , ALL rubber fuel lines, metal fuel lines under the car (I made up copper ones), Carburetor (service kit or replace, there can be internal gauze's on inlet tube plus gauze strainer beyond that etc),Jets and fuel pump. If you are using swirl pot /fuel vapour separator replace that also. Put it this way if I get another carbed VW I will probably replace everything because you tend to chase the source of rust/perishing throughout the length of the system anyway.

[daffy.dub]

Ok, thanx for that. I can rule out the carb, it's brand new. As for the filler neck, I have a brand new one of those too, just waiting to put it on, so will check everything else around that. I don't really like tampering with things that VW put on the car (apart from carb) so will go down the route of checking all and replace. Thanx again for the advice.

[unknownmale]

Just had this problem, Don't have any welding tips around so I cut out a presta style valve from a bike inner tube which works well...plus you can open or close the valve more or less to change the fuel restriction.