I think my car has been running rich lately and I was talking to a friend about it. He said there should be a little screw connected to the front left strut tower (left side when looking at car from front). He told me to try turning that to the left and see if that helps. I looked on my car and there is nothing there. I checked it out on his car and it is pretty easy to see and in plain view, but there is nothing there on my car. He has an 87, and mine is a 90. I am just wondering if it is in a different spot on the 90's or if they do not have one at all. I have also seen this same screw on a different RX-7 and it is also on the left tower. Any help would be great, thanks.

 

it doesn't exist on series 5 (89-92) FCs. You have a little screw on top of the throttle body that controls a/f at idle. But I wouldn't go messing with it unless you have a damn good way to tell what your a/f ratios are.

 

And also, that screw is only to adjust the idle mixture. Has no effect otherwise.

 

yep, worse that will happen is the car will stall...adjust it at full operating temperature.

 

Actually, he should just leave the screw alone.