when the rpm just hit 3000rpm, its automatically loss power.

My car have been replace from auto to manual transmission with original auto ecu. But when the rpm just hit 3000 rpm, its automatically loss power..then i stop the car while engine start..after 1 minutes back to normal..my speedometer is not work after installing manual gearbox.can u help me

mitsubishi lancer 7.

4g18 engine