vapour lock- any ideas?

Hi

Cars suffering vapour lock, runs but under load it stumbles and dies. The cars a clipper running a weber, new tank, no issues with the filter or inbay hoses and ive also swapped out the vapour seperator and pump (twice) to no avail. The fuel pipes have been inspected too and blown out…all ok.

When the car dies, i lift the bonnet and theres no fuel in the inline filter. If I pop the pipe off the filter the car will then fire on turnover and run again.

Im now changing to a electric pump just incase its a not sucking enough to feed the weber, and in the heat its vacuuming.

Anyone have any ideas?

Thanks for your help.
Ross

Check the hole in the fuel filler cap is not blocked.

Or the wrong cap is fitted, the GTI ones were non vented (Ohne Lüftung as opposed to mit Lüftung)

Look on the bottom of the cap for these German words

lhasadreams said

Or the wrong cap is fitted, the GTI ones were non vented (Ohne Lüftung as opposed to mit Lüftung)

Look on the bottom of the cap for these German words

Its vented thanks for the pointer though.

Cero said

Check the hole in the fuel filler cap is not blocked.

Sound like a numpty…howdo I check this?

Cero said

Check the hole in the fuel filler cap is not blocked.

Sound like a numpty…howdo I check this?
Thanks

Arghhh, electric fuel pumup and change of cap and still problems

Does it still have a metal diffuser plate below the carb ? Can't remember if they all came fitted with this …
Check the float valve is set to correct height as it could be expanding with the heat and stopping fuel delivery.

Cero said

Does it still have a metal diffuser plate below the carb ? Can't remember if they all came fitted with this …
Check the float valve is set to correct height as it could be expanding with the heat and stopping fuel delivery.

Hello.
No, its a rubber one. Float seems to be ok. Car will restart ones it cuts out if i disconnect the pipe from the filter  to the pump and reattach…arghh!

What pump you now running and is it an in-line fuel filter? You sure the floats not sticking and set to the correct level ?

Cero said

What pump you now running and is it an in-line fuel filter? You sure the floats not sticking and set to the correct level ?

Mechanical, suctions fine and even swapped out to an electric to see if that would help- no joy. Running a filter before the pump (again fine) and swapped out the swirl pot (twice) to no avail so now running without with a restricted return- runs better but the lock has occurred again

I've just had a mega PITA with a pattern fuel tank causing poor running. Mine's a GTI but could this be your problem too?

Early-1800 said

I've just had a mega PITA with a pattern fuel tank causing poor running. Mine's a GTI but could this be your problem too?

Sadly not the pump- 2 different mechanical ones and even an electric…no joy.
Had it out today and when it stopped the only way to restart quickly was to unplug the fuel feed to the pump and reconnect- started and ran perfectly

Check the rubber flange the carb sits on, they can spilt at the sides which is hard to see, run the car and wobble the carb to see if there is any difference in running. Then try resticting the fuel return, info on doing it here (Scirocco has the same fuel system etc)
http://sciroccoregisterforum.co.uk/carforum/viewtopic.php?f=12&t=15397

mark1gls said

Check the rubber flange the carb sits on, they can spilt at the sides which is hard to see, run the car and wobble the carb to see if there is any difference in running. Then try resticting the fuel return, info on doing it here (Scirocco has the same fuel system etc)
http://sciroccoregisterforum.co.uk/carforum/viewtopic.php?f=12&t=15397

Thanks mate- did the return last week…as per this and sadly already changed the flange…I'm losing the will

I'm in the exact same position, even tried changing back from elec fuel pump and pressure regulator, to original mechanical pump and fuel bowl……. now it just seems not to pull the fuel through.  Got to the point where i'm very close just to selling the car