Power loss till 5,000 rpm

[chriskb3]

The motor is a m20b25 with a Jim C 93 octane chip. When I accelerate in any gear the engine does not pull as hard as it should and at some points it jerks as if I am pumping the gas. The engine slowly creaps up until 5,000 rpm where it then feels like I just hit boost on a turbo'd car and revs strongly to redline.
The spark plugs (bosch supers) have been replaced within the past 100 miles, along with a valve adjustment. The tune up seemed to not have any effect on the way the engine ran.
Any ideas on whats causing the motor to run this way?

Thanks for the help.

[nando]

Afm?

[E34Project]

did you have this problem before u put in the chip?

[chriskb3]

nope, ive had the chip in for about 2 years now. The power loss started occuring this past year.