RX8 sat for a year what do I need to do before I try and start it
A fresh tank of gas and an oil change would be good. Charge up the battery as it is probably dead or weak.
I am getting a new battery, but I read I might need to inject some oil or transmission fluid into the spark plug holes for the apex seals, so do I need to do that?
That would not hurt. Don't put too much in though and spin the engine with the plugs out before starting.
Yes a little tranny fluid will really help, but turn the engine over by hand before spinning it with the starter. Best replace the plugs while you have them out, and get the right ones, incorrect plugs can damaged the engine internally. Once it starts do not turn it off until it reaches full operational temperature, so you need to make sure the coolant is good and full. Rotaries are strange creatures and everything needs to be right for them to operate properly especially in the 2000 model years. Then after you get it running and check the brakes and electricals to make sure it all works then change all the fluids you have not yet done, gear box, differential, brake fluid, etc.
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