If you have replaced the transponder unit at the ignition lock then that should be enough.
If it isn't working or recognising the key then either the unit is faulty or the chip in the key is faulty or has been supplied wrongly.
Easiest way to check is with a suitable scan tool.
The scan tool needs to be able to read the immobiliser data as well as the engine data.
i took the engine, chip reader, chip and ecu from a insurance write off i bought and drove the car before removing the engine,
i have not changed the ignition barrel but took the chip out and put it in the original key
Did you not change the receiver unit around the ignition barrel?
Yes, that's what i call the chip reader, the black ring around the ignition with a box on it
No matter what i do it still comes back saying No/Wrong immobilizer signal and the engine management light just keeps flashing
It sounds like the transponder chip is faulty.