uncured misfire

Hello guys

I run a 1990 cabriolet on a 1.8gti engine down for approx.140k
I recently developed a nasty misfire that seemed to prefer to rear its head as pulling away after changing from 1st to 2nd
I have changed the dizzy cap, rotor arm, plugs and upgraded to spitfire leads and it did improve the overall performance but not the misfire, it did however make it less frequent.

Plus since changing all the above parts I have develeped a knocking noise. I am new to water cooled scene and ultimately this forum as i have always run a 66 bug.

Would appreciate any help anyone can give> she turns heads for the wrong reason!! :dontknow: