mine "coughs" on hard acceleration, will stall if i dont take my foot out of her quick, its almost like as soon as i hit the gas, someone turned the key off... and when driving a steady speed, lightly on the accelerator, just enough to hold say 30 mph, she sputters like she has a clogged fuel filter, cant tell you how many times i changed the dang fuel filter hoping it would help... then i spent $10 on that star tron fuel treatment and all problems STOPPED.... i mash the gas and my old tired 3.8 229 spins the hell outta the tires... my wife couldnt believe the change in the car, her exact words were "all the time you spent trying to fix this ****in thing and all you had to do was add a bottle of blue crap"... then she laughed at me... (so i put her in the trunk) not really, but i wanted to... ANYWAYS, i have found, the older the car, and the more it is driven, the more they tend to hate corn gas...