I've only encountered coilpacks that were completely working or completely dead. I was wondering if they slowly die. My 98 maxima has a misfire at idle. It doesn't happen all the time. But when it does happen, it only misfires 1/4 of the time. So its not a DEAD misfire like i'm used to. I dont get any CEL oddly for this, even tho 100% the car is misfiring. The rpm which is normally at 750 at idle dip to like 700 and back up again. So far no obvious vac line leaks, plugs look decent and was recently changed about 8k miles ago with NGK plats. Maybe the IACV could be it.