help !

[gbw1966]

hello guys i own a 1998 punto s 60 and im havin a problem lol not new i guess . the car starts and ticks over fine no problem sweet as a nut but when i go to set off i have to rev it excessivly or it stalls , doesnt matter what gear its in if i put my foot down it coughs n splutters then picks up all at once. i have changed plugs and all ht leads new air filter and oil change , was suggested to me that it may be an earthin prob but that dont ring true and i have checked all eathin cables and all ok just wondered if anyone had any advice or had a similar problem ? lovin this site thanx guys , ben