Hi and wecome to Just Answer
the first thing with the rotary RX7 is to make sure the spark plugs are spot on and correct type fo the rx7 if in doubt replace tham as they can foul up or start breaking down and because its a rotary missfires feel a bit different also being a new car to your self you can never trust service history
Also check all the inlet system for any air leaks befor diving in and adjusting the system
Have a look at these and let me know if you need more help I,m glad to be of assistance
Mechanic
Qualified Mechanic & Auto Electrician ex RAC Patrol & Technical Liaison Manager