All distributor components have been replaced.As well as the starter,alternater and the cutting and crimping of new spark plug wires the battery is good and the spark plugs are clean and gaped to correct specification.
What year and make of vehicle? The distributor components are only a sub-system of the entire ignition system (associated wiring, fuses, coil(s), ignition switch, etc.etc
Power supply to the distributor would be a good place to check Not knowing what you are working on hinders a more specific and detailed answer.
You'd get a better answer if you'd tell us make, model, year and engine. Is there a crankshaft sensor outside of the distributor? Is the ignition coil built into the distributor?