hi sages- this may be a job for superman or if he is out of town sage art ben. have been wrestling with this for a year now. 92 volvo 240 in south florida where it is warm most of the time and most of the time this problem doesnt exist. simply put, on cold or damp morning startup and for 10 min of initialdrive time, engine misses badly and bucks on acceleration. it acts just like it has a bad sparkplug or two , a burned up rotor or cap or bad plug wires. otherwise when warmed up or if its a warm day engine runs smooth and powerfully. regularly gets 25mpg around town. have thoroughly checked plugs, cap, rotor and plug wires. on dark cold night i see no sparks jumping around wires. have had this same problem on slant six dodges and other carberated cars. only vehicle i have had which doesnt do this is my 4 cyl. saturn L100. my theory now is that this volvo has an engine temp sensor which runs the temp gage on the dash(gage reaches 1/2 on the needle after 15 min. of driving) and a coolant temp sensor. i think both or one of these go to the engine computer and signals the fuel system to deliver a rich or lean mixture. my question is if one or both of these sensors went stinko wouldnt the computer mistakenly tell the fuel system to deliver a lean mixture to a cold engine thus producing this symptom. uncle moe says dont worry about it as it is a common problem with older cars especially with 4 cyl engines, even after a dealer soaks you for a repair that doesnt work. what say you good folks. about ready to give up and shut up. thanks tons oldduke