Copyshoppeman

Has anyone else heard of installing a ground wiring kit to help with the rough idle that almost all rx8's have.

fxdsconv2000

Do a search you will find lots of information.

A grounding kit will even out your electrical system. For instance no or little rpm change when turning on the headlights.

Magic8

it doesn't help. I have ground wire and it will rough idle from time to time. Only thing that seems to help is the infamous "M" flash.

psionic1

I have rough idle when I start it cold in the morning. Ground wires did not help that. M flash did not help either. After it warms up, idle is smooth. But, it always was even before the M flash after warm up.

I added the ground wires simply because I wanted to tinker, and it was a cheap, easy mod.

Copyshoppeman

Well I got the M flash about 2 weeks ago and I don't notice any difference. The dealer went ahead and did it for me when I took my car in for a routine oil change and if he hadn't, I wouldn't have even noticed. All I use is 93 octane and my car seems to run better in the morning when it's cooler versus later in the afternoon when its hot and humid. Also in the afternoon when I have to turn my A/C on the idle is even worse. Sitting at red lights is torture because I think it's gonna stall like it already has! Just imagine, brand new rx8 stalled out on a busy highway! Man was I embarassed!

Magic8

The thing is it won't stall, just something you have to live with. Some one can correct me, but I believe CZ (Canzoomer) or Rx-Friend theorize that the injectors are really oversized for this application. So at idle, the ECU cycles the injectors on and off, therefore you get that studdering feeling.

Zedcaster

Not to come off like a noob, but is there not a way to increase the idle speed? When my VFR is doing what is being described, I just ramp up the idle speed by 100 or 200 RPM and it smooths out.

PS my 8 stumbles a bit.

bxb40

Had the same rough idle problem on my old Firebird - put 300 extr RPMs and was gone. But the idle speed and pull of the car changed too. It would climb without accelerator pressed a light incline! Kind of usefull in city stop'n go (only use the brake pedal, no need for the accelerator).
So, how to do this on the RX8? I assume it is a computer thing - like everything else nowdays....

rxeightr

Try using 87 octane for a few tankfuls. Other Club members have shown this corrects the rough idle.

Copyshoppeman

So how do you increase the idle speed? If it's a computer thing, will the dealer do it for you? My guess is they probably won't and say it'll void your warranty or something like that!