scirocco gt2 1.8 runs a bit dodgy

[cotney05]

hi as the title says my babys running dodgy...just purchased her a week ago and she isnt rite ...when you first start her she runs sweet as a nut except for the favt she revs at nearly 2 grand and theres a tiny flat spot on first acceleration.....as she warms up the idle drops gradually till eventually the car reaches temperature and cuts out as you slow down to approach junctions...i jave fitted a new base gasket for the carb and tweeked the timing which helped slightly but it aint righte still...any help pplease would be great ..thanks