325i automatic hesitation/spuddering problems please help!
i have a 93 325i 4dr automatic. alright so ive owned the car for about 3 months, soon after i bought it driving on the highway or at a constant speed it seemed to loose power even when the throttle was at a constant spot, it felt like you let off the throttle alittle then it would speed up again. well it soon got worse and in the last month it would spudder under like 3000 rpm and hesitate and you would hear an occasional popping under the hood like a backfire. IT ONLY DOES IT WHEN ITS WARM, everytime i start it after sitting all night it runs perfectly fine and most of the time doesnt start spuddering or acting up till i shut it off and start it again or it warms up to normal operating temp. i assumed it was an ignition problem or a fuel pump. on friday it started running terrible with an obvious miss and i pulled the large plastic cover off the top of the valve cover to expose the coil packs and i discovered #2 coil (the only replacement coil the car has) was arcing from the windings onto the valve cover. so i removed all the coils, cleaned the plugs, got a used coil from a junkyard and then installed everything. it started up and ran fine, the miss went away. then i drove it around and it ran fine even after it warmed up, i shut it off, waited 4 or 5 mintues and started it again and it ran bad again. it seems to spudder alot more under load and it never does it when its cold only when its hot. it doesnt have a check engine light on but it does come on ocasionally for the 02 sensor. i also removed the throttle position switch cause i thought maybe that was the problem so i let it run in limp mode and as soon as it warmed up it ran the same. Someone HELP! btw. i havent checked fuel pressure