Hey everyone, my friend has an rx8 that’s been sitting around for roughly 2 years without being driven or ran. We put a new battery in and tried to fire it up and it struggled to start. It always turned over but only fired up after a few tries. When it finally did fire up, it had a rough idle and even shut off a few times. After a few tries it idles fine but sometimes goes back to the rough idle. It doesnt really want to fire up after the motor is warm but eventually does even if the motor is warm but struggles. There is no check engine light at all. Any idea what this can be? In my opinion it revs fine and I don’t think it lost any power. When you go out for a drive it drives fine, shifts fine and no problems. When you get to a light it will sometimes have a rough idle and shutoff and sometimes it idles fine. Thanks guys

 

when you disconnect the battery it takes a few drive cycles for the computer to relearn which could cause the rough idle. i would change air filter, ignition stuff, clean the maf and ess and do the 20 brake stomp. also i would drain the gas and fill with fresh go go juice

 

If your friends RX-8 is a MY 2009-2011 then the Series 2 reset is:

Disconnect Negative Battery Terminal and
press ONCE on Brake Pedal WITHIN, 60 seconds.

 

Thanks guys, we will give all of those things a try. Hopefully it fixes the problems. I cant imagine it being anything too serious especially if there is no check engine light and it ran fine before it was put away.

 

2 year gas is no good. Is the tank full? If so, you'll have to drain it or you could try adding Seafoam in the tank to recondition it. If there is space just dilute it with fresh gas and go easy until you're sure the old gas has been burned off.