Did you Google? I found this in 3 seconds bud -
put a different engine in it !!
dont waste ur time trying to tune a 1.4!!
i put manifold-decat-catback system on mine and induction kit, n that got it upto about 110bhp! which is very good for a 1.4!! all in all probably cost me about £500 quid, cud probs squeeze bit more out by getting it remapped, but tbh u cud get urself a nice b16 fitted instead!!!
if you want a quick boost, do a cylinder head swap like edd said, get it upto about 135, dont expect anymore with that block