Help Please

Hi to all my Mk1 golf 2004 Chico Carb is not idling it is definitely a fuel issue i think, if i rev it it stay on but as soon as i dont rev it dies. i have checked all filters and they are clean i have checked the pump which is working and the lines going to the carb that is also working fine, the engine valve cut off switch i have also cheked with the fuse.

any thing else that i need to check ?

FYI the plugs are also fine.

Thanks!