i drive a 91 grand prix with the 3.1 and automatic that i drive daily. it seems to be missing every so often, either that or flooding. i have had repeated problems with some of the computers and I have ended up replacing most of them including the one that controls the spark distribution 3 or 4 times. every time i replaced it it seemed to take care of the problem for a week or so before it would start missing again. i have cheacked all the plug wires and they arent shorting, the more i drive it the worse it gets and i have noticed the milage drop slightly. could this be related? has anyone exsperianced similar problems?? any help is appreciated, thanks.