Alright so after fixing the missfire i had (thread down the list abit) i now have another problem,

The car is lacking its umph, now its only a 1.6 but i no how much pull it should have. Say im going along 50mph in 3rd, if i floor it the car goes but its lacking in the power. Theres a stretch of road with a hill that i could hit 80mph at the crest of the hill but now i can only manage 70-75. Also sometimes after a short drive (long for engine to get warm) if i go into a shop and go to start the car it struggles like a weak battery, the batteries new and i tested the alternater and its fine.

Any ideas what could be wrong.??