1998 Chrysler Neon car bogs down while throttleing

I have a 1998 chrysler neon, the car will start fine, idle great with no surges but when you step on the throttle it sputters and or bogs down. When you quickly step on the gas to full throttle, it just bogs and does not rev. If you slowly give throttle, the car revs to much much higher rpms like it should but again quick full throttle bogs it down.
The same thing applies when you put it in gear or under load, the car will hesitate and sputter untill it reaches it seems like the right amount of air and you can feel the original power but then cuts off untill you hit 2K rpm steady or higher, then the car seems to run fine. At highway speeds, the car runs great no hesitation under load at higher rpms. At high speeds when the rpm drops a little when the tranny is not locked, you can give it throttle and it responds beautifully. The problem is when it is throttled from lower rpms to achieve higher rpms. Sometimes it does it and sometimes it seems to run half way decent. Please help, don't know what to replace, the fuel pump or the ignition coil pack/wires, I have already replace the sparkplugs.
Thanks!