a2 starting problems

[paul mock]

i wonder if anyone can help me i am having terrible trouble starting my 51 plate a2 1.4 petrol from cold and when warm It turns over but doesnt seem to catch however it does eventually starts but it splutters into action and there is a strong smell of petrol however this clears quite quickly once it is running. I changed the spark plugs the other night this made no difference this is really annoying any help would be much appreciated .(i did post this under another title but i dont know if it was the right one)many thanks