I have a 2002 4.6 Ive had my pony for a little over a year. Im having a surge problem. When i accelerate the car surges. the best way to explain it is... upon moderate to heavy accel (like getting on freeway) it feels like the trac control is kicking in but its not. i get the lug, smooth, lug, smooth, lug, smooth acceleration feeling. what could be going on. ive ran a few tests and im kinda stuck here.

 

Check your fuel filter or fuel pump. Sounds like its getting enough fuel, not getting enough fuel, getting fuel, not getting fuel, etc...

 

OP..Are you running any tunes?
Have you ever changed the spark plugs or tuned it up ?
Maybe bad gas?


Also, If you run your defrost or AC and its low on refrigerant will cause a surging idle and make car surge while driving.(not enough pressure in AC system)

These are a few things that will cause your issue.

 

A stuck/sticking EGR valve will also cause that...