Ford - Freestyle :: 2005 - Surging And Hesitation While In Cruise Control At 70 Mph

I have a 2005 Ford Freestyle with 59,xxx miles. My wife and I drive it less than 7,000 miles p/year. About six months ago it began to surge (we had already taken it back to the dealer for some work on a recall related to surges while idling). However, the surge that now occurs is not related to the recall--it can happen anytime, even when on the highway while in cruise control at 70 mph. It makes the driveability of the car questionable. We have had it back to the Ford deal repeatedly, only to be told a number of high dollar things that seem to be based on guesses rather than actual data. No codes have come up with computer diagnostics.

We have also taken to independent mechanics, only to be told there is nothing wrong. Only once did a mechanic say that he 'felt' the surging when he test drove the vehicle. But even then, the shop said that they would have to do a tune-up (which raised a red flag with me because tune-ups no longer seem to be the proper term to be used with modern engine maintenance). I did a lot of research and as a result I asked a mechanic to test the fuel pump. The result is that the low pressure was 39.5 lbs, and, the high pressure was also 39.5 lbs.