Four things come to mind...

One, is the star shaped "wheel", the reluctor, on the distributor shaft under the rotor.

Second is the magnetic pickup which senses when a point of the reluctor passes it, telling the coil "when to fire" a plug.

Third, is the ignition control module, which governs the whole duraspark system.

Fourth, worst case scenario, is the drive gear on the 2.3L distributors has been reported to sheer off the retaining pin that holds it in place on the distributor shaft, keeping the rotor rotating in sync with everything else. To check this I would disconnect the coil and pop off the distributor cap. Crank the motor and have someone look and see if the rotor turns.


The first three, as far as I know, are just part swapping to determine which could be bad.