'91 Grand Marquis w/ stock AOD tranny and stock remanufactured Jasper 302 engine. Not sure how to exactly say what is going on regarding is it a miss, hesitation, etc but this started last week while driving 75MPH on the interstate on a trip from VA to NC w/ cruise control engaged and A/C off. The engine felt like it had a bump in it where you could feel it inside the car and it started several hours into the trip, so the engine was good and hot. Could have been a miss or hesitation too. I coasted to 65MPH and it went away. On the return trip back from NC to VA driving 65MPH no problems at all. Then this week at 45MPH while the engine is cold but warming up it does it again only I don't have the cruise control on. It went away the further I drove. This seems to occur randomly while lightly feathering the throttle to maintain speed or under slight acceleration to gain speed. No check engine lights are on. Any thoughts on what may be causing this?