Windstar cutting out @40mph and 55mph

My 2002 Winstar has about 80,000 miles and around 40 mph and again at 55 mph it seems to be cutting out a little. When I open up the engine and pump the gas quickly I can hear a little air coming from under the head it sounds like. I know that vaccum tubes can be a problem. Is this what it sounds like? Or what else could it be??
Np

When was the last time you changed the fuel filter? :shakehead

In my experience, Windstars tend to have very noisy intakes (i.e., lots of air movement sounds), even when running properly. So what you're hearing doesn't necessarily indicate a leak, even though it might be a vaccum problem.

Let's start with basics: Is your Check Engine light on? Are other tuneup items up-to-date (air/fuel filters, spark plugs, etc.)? Is the 'cut-out' consistent (i.e., does it happen that same way every time, or does it vary based on temperature or other factors)? Are there other symptoms that might help diagnose the problem?

The fuel filter has never been changed and it has never been tuned. It is just a little shaky for just a second at about the same 40 and 55 mph every time. Should I start with a tune up??

HI FOLKS, I AM 69 YEARS OLD AND CARS ARE GETTING HARDER AND HARDER TO FIX! I HAVE A 2001 FORD WINDSTAR THAT'S GOT ME STUMPED...............

PROBLEM? MISSES WHEN GOING UP ANY DECENT HILL, BUT RUNS SMOOTH ON THE FLAT HIGHWAY. IN OVERDRIVE, IT STARTS ON A GRADE IF I AM TRAVELING 70 OR SLOWER, AND CAN ONLY BE STOPPED IF I PUSH THE OD BUTTON AND TAKE ER OUT OF O.D.IT WILL MISS IN THE 3RD GEAR IF RPM"S ARE BELOW 2K.IT HAPPENS MOSTLY WHEN ATTEMPTING TO ACCELERATE UNDER LOAD.I HAVE REPLACED THE PLUGS WITH DOUBLE PLATINUMS,THE ORIGINAL IGN WIRING WITH THE HIGH DOLLAR SILICON FROM AUTOZONE, THE FUEL FILTER, AND AIR FILTER. THIS HAD LITTLE EFFECT IN FIXING MY PROBLEM. MILAGE=120,000 . COULD THE COIL PACK CREATE THIS CONDITION? ALSO I HAVE READ ABOUT VACUUM LEAKS IN THE INTAKE DUE TO THE METAL TO PLASTIC ASSEMBLY OF THE INTAKE MANIFOLD. WHAT SHOULD THE VACUUM READING BE IF ENGINE IN NORMAL? I CANNOT HEAR ANY UNUSUAL NOISES COMING FROM THE ENGINE, SUCH AS A HUGE VACUUM LEAK, AND I AM MEASURING A 15 ON MY VACUUM GUAGE, USING vacuum take off ON THE FRONT PVC VALVE LOCATION. THIS LINE COMES STRAIGHT OUT OF THE MANIFOLD. TIMING IS CONFUSING TO ME...WITH THE ABSENCE OF A DISTRIBUTOR AND IGN TIMING CAPABILITIES, I GUESS I AM AT THE MERCY OF THAT CPU , TRUSTING IT WILL GIVE ME THE RIGHT TIMING, I GUESS IT BASES THIS ON THE ENGINE VACUUM, AND ADJUSTS THE TIMING AS ENGINE CONDITIONS ARE SENT TO IT. I AM GUESSING THE FUEL INJECTORS ARE CONTROLLED IN A SIMILAR MANNOR....ANY HELP ON THIS? ANYBODY OUT THERE HAVE A CLUE? . ONLY ALARM IS PGR 101. THAT UNIT CHECKS GOOD, BUT COULD BE FAILING DUE TO A VACUUM LEAK OF THE LINE PROVIDING THE VACUUM, OR A CONTROL VALVE THAT ACTIVATES THE VACUUM UNIT ON THE TOP.

Nperry,
I would start with the fuel filter, and even a dose of Berryman's B12 Chemtool.
A fuel delivery problem will not light up the check engine light or set a code on it's own.
A tune-up may be in order, plugs, wires, air filter.

Leon & Nperry,
Check out the posts on the "P0171 & P0174" fix.
There is a TSB that has you replace the isolator bolts inside the upper intake manifold with ones that have isolators that are more tolerant of oil.
You could be in the early stages of the vaccum leaks caused by this.
The PCM tries to correct for things, and eventually the leakage gets to the point that it cannot correct, and it lights the CEL and gives you the lean codes.
Almost NEVER is the lean code or codes caused by a oxygen sensor, rather, it is the extra air getting in.