Newbie with Mis-firing :(

[jamie_300 0]

Hi there I just bought a 2 litre 8valve Corrado

 

But I'm having a few problems with it though

 

On the way home I noticed it began to misfire at 45-50 mph

 

So my dad and I replaced Sparkplugs, air filter and dizzy cap

 

And it seems to be worse as it now splutters at low speed

 

I've bought a new oil filter and We're going to do an oil change over the weekend

 

Does anyone else know anything that might make it better?

[Roger Blassberg 0]

Rotor arm?