DriveATransAm

all of a sudden my car is surging like mad lately. all the way to the point if im stopped, it will die. with the underdrive and the cam it usually stays right past the line (what is that, 13v?). little higher on startup. it was on the line today, while it was surging and i would just watch the needle drop a little bit every time it surged. at idle speed it seemed fine. i get no ses lights? whats the deal? car is dyno tuned and i havent touched anything since the last time i drove it.