take it apart and reattach it all check and see if the distributor cap u got is exactly the same as ur old ones, make sure u put the plug wires in the right holes and on the right connectors of the dizzy, and compare the old ignition rotor to the one u just installed to make sure its the same, and crank down that little screw that the rotor in there to make sure it doesnt have too much play, just go over everything u did to the car and eventually u'll find ur problem, and also double check the plug gap, good luck let me know if u fix it