missfire @ 2500 3000 rpm?????

[new jack e30]

1991 318is m42. the car has been missing at 2500 3000 rpm .changed coils, plugs, mass air flow, gutted the cat, fuel filter,checked fuel pressure is good disconnected the throttle position sensor and started and same problem rev it up and it misses like a rev limiter is kicking in. can anyone help me with what this might be i dont know what else to try.