5.3 swap code PO200 injector circuit open

[Ken Davis]

My 72 with a 5.3 swap has been running fine yesterday the light came on and the code PO200 injector circuit open came up on the scanner. The injectors were dirty and were cleaned in the beginning of the swap. The truck is not on the road it has only been backed out from the garage. What should I look for I cleared the code and let the truck warm up and the code reappears.
Thank you for the help.