I hope someone can help, I have a 1985 Fleetwood Brougham 4.1 The car when driven "normally" feels like it has mis-fire, however when driven hard this mis-fire seems to go away. It seems like it is greatly affected by temperature and humidity. Hot temp and high humidity it runs like it only has five cylinders, cool temp like in the fall it runs "almost" perfectly. cold temp like below zero C. chugs gas at a frightening rate. I have put new Oxygen, Baro and MAP sensors as well as plugs, wires and rotor cap. The only code which sometimes comes up, after driving at steady speed for some time is code 39 TCC engagement problem. Car otherwise runs great, hope someone can help as it will soon be going away for the winter.