Just to get this right in my mind , you bought car and it was running fine , then you did your mods and fitted the beige injectors and when you ran it again it had this problem , how long is it between it running ?

Had one not long ago and the fuel pressure reg had gone faulty with standing and it was giving massive pressure , but likewise it could of failed in a low pressure mode so with the beiges in it was actually running better as it was delivering fuel at lower pressure but through bigger injectors , and now you have put blues in they are not delivering enough to run .

The TPS being disconnected and it running better may well be because it goes to a default half throttle position if no feed seen to prevent running weak and then with low fuel pressure it richens it up to the point that it can run .

The TPS does share the feed and earth with the map so it could also have got a short within the TPS causing the voltage to drop within that feed to the point where the map , act , cts and co adjuster so a TPS fault could a LOT of issues depending on its failure mode .