99' taurus se 3.0 vulcan,80,000 miles.I have noticed while driving at 55 to 65 mph the car would seem to "coast" for a few seconds then regain power.I have only had the car for a month.At first it would only happen when I had the heater on so I thought the intermintent drain on the elec. system caused a surge.Then I realized that the heat was either on or off...no compressor to change draw on battery.Tonight it did it with the heat on so I turned the heat off and a few minutes later it did it again.Could it be electrical,fuel,transmission or sensor?

possibly sounds torque converter related