you need to get it checked out properly really as internet diagnosis is not easy,but if you have changed all the ignition parts(i.e plug's,lead's,dizzy cap rotor arm,coil,ign amp)and set the plug gap's to .6mm rather than .9mm and that hasn't cured it,then the next logical thing would be to change the inline fuel filter,and if that does'nt work then check the fuel lines for leak's and the fuel pressure regulator (is the vacuem hose attached properly,is it working?) if that does not work then change the fuel pump, i hate typing