Fuel metering problem

Hi all and thanks for looking.
I'll start from the beginning.
The car has been sat for 19 years , when trying to start it, it wouldn't go . Fuel was being dumped into the bores as if on full throttle, so I have changed the metering head over and got it to run (kind of).
It wont tick over, really flat and wont pick up. Pops and bangs a bit too, just like it has been extremely retarded on the ignition timing . If I unclip the air box and lift the flap slightly with my finger it runs sweet as a nut. Also if I push up on the flap / plunger in time with opening the throttle I revs free as a bird .
It seems as if there is to much pressure for the vacuum to lift the flap by itself.
Do I try and play with the mixture screw?
Any suggestions ????
Many thanks
Jase

have a read thru this and do all the basic kjet tests, just ignore anything 16v specific:
http://www.vwgolfmk2.co.uk/forum/viewtopic.php?f=37&t=25972

ignition timing is done at idle with dizzy vac line disconnected and plugged, for the idle and co thats just done at normal idle

in particular look at the flap to ensure its central, clean and height is correct

Hi john , thanks for the reply.
I will have a look of the position of the air flap next as I'm convinced the problem lies there. Won't be until the week end though.
Will let you know how I get on.
Cheers fella
Jase

Does the flap look really clean or are there any brown varnish like deposits round its edge/base - likewise the plunger in the metering head, if either have any dried on fuel deposits could by sticky enough for air/ vacuum pressure alone not to be strong enough to move. Mine was like this after 14 yrs standing but a good spray with carburettor cleaner got them both working as they should.