Well considering you did not have this issue before replacing the rotor and cap, chances are even money it has to do with something involved with their replacement.
Faulty rotor or cap or both.
Wires not fully seated.(you wouldn’t be the first to be bitten by that)
Wire damaged when it ws removed.
Might try doing a visual at night with the engine running and look for any sparks jumping.
Might also try running a test light clamped to ground and run it all over the the cap and wires and look for any arcing.