00 Sportage Won't start?????

Had a knocking rod....so we parked it and and a week later went out to show the Mechanic what it was doing and it would not start...So the Mechanic went ahead and rebuilt the bottom end of the motor put it all back together and with starter fluid it will start and no knocks...We have now replace the ECM, Crank Sensor, Cam Shaft Sensor, checked the fuel pump it's working??? Hooked it up to the computer and it is reading NO codes at all...:banghead: