Originally posted by randomds:

as a mechanical engineer myself, i truly believe this problem is directly related to the newest style pump Ford sells. if i had to guess, id say the pumps natural frequency is oscillating against another freq. the car produces in that rpm range in third gear, causing the fuel injection fluctuation. either that, or injection timing and flow rate needs to be modified for this pump.




I totally agree. I was thinking that it could be the EEC reading a different impedence off the new pump (one that it is not programmed for). The frequency oscillation does make sense, however, because you can hear an on/off note with the engine under acceleration. I'm on my way down to the Ford dealership to see if any contour's they've replaced the pump on have had this problem. The issue is, we can't go back to old-style pump without replacing the tank, as we had to cut out the retainer ring in the bottom. (doh!)

-Chris 2000 SE Sport V6 5spd (all stock except for EO brakes)