I have a 91 LX that jsut started to sprout a missfire. Ive head this car for awhile but havnt drove it all the time. it has 132k miles but it runs great otherwise. The missfire just started happeneing when it got cold here, and when i say cold i mean 15-20 below zero. Ive replaced the spark plugs 2 months ago so i doubt it could be that, but i will check them anyways. In WI we are having issues with reformulated fuel causing problems with injectors and even on cars that have only 6,000 miles. Its been mainly happeneing with GM vehicles but for is up there to. I am wondering if one of my injectors is intermittinly sticking. Its dosnt missfire all teh time, when its cold it will do it here and there evreey couple of seconds at idle. When its warm it wont do it at idle but if a hold a constant speed around 60 mph or so i can feel it surge and buck very lightly but i do notice i will loose speed gradually untill i push done on the accelerator a bit. Im not sure where to start, coudl be an injector, TPS, MAP, MAF. IABV. Any one have this sort of problem before?