Car: 1998 V70 2.5 10V

Problem: Car will misfire/stutter as it hits 3500rpm+...ie it won''t rev cleanly and lacks power.

So far the following has been checked, plugs, cap, rotor arm, HT Leads, Timing...it also appears to have had a new crank shaft position sensor fitted and none of these items have cured the problem.

Going to have the fuel pressure checked but is there anything else that could be causing the problem.

If it had a Air Flow Meter fitted I would say it shows all of the signs of a failing air flow meter, but in this case, being a 10v model it doesn''t have an air flow meter.

Any suggestions????????????????