No idle below 2000 rpm rich running

[Steller Engineering]

Good afternoon its finally time to run our restoration project up but I'm struggling with it running far too rich so hopefully someone here can point me in the right direction.

Its an ex BSCC touring car from 1986 that I came to in a state of partial rebuild and have had to source parts and attempt to re engineer some other bits

As far as I can tell I have the original loom, ignition pack, ecu and some injectors from Flo and it started first hit of the button with a bit of extra throttle. but a post collector lamda sensor is giving me a constant 0.8 and it will stall out below 1500 rpm having got it warm and tried swapping out fuel pressure regulators and resetting the throttle pot it wouldnt restart because the plugs were too fouled, cleaned them up and refitted and it starts again at least.

What might I have missed that would allow it to start but run rich?