Rob, the symptom of a cylinder not working is not necessarily caused by the ignition.
Your car probably does not have OBD2 because it was built before 2000.
I had the symptom of a cylinder not working some time ago. My OBD2 reader was a great and quick help. It was a weak contact in the electrical wire to one of the injectors. Therefore she run only on three cylinders. These injectors and their electrical supply lines are in a wet area where rainwater constantly penetrates. If your Rover engine has electric injectors then it would be worth trying to check these contacts as well. Here is my former thread.
http://www.talkmorgan.com/ubbthread...injectors-issues-today-solved#Post678897
