Good to finally see a build thread, been following you in instagram for a while looks great, nice figure out of the vf24 I'm running one now nice to see they can get into the 300s easy
No your right, the next port of call I would do is check all plugs related to the injectors and follow it back to ecu make sure there are no breaks in the wiring somewhere. Even the fuses
I had an issue with my tial where the grub screws that hold the valve on in the diaphragm came off and was leaking through them holes, I'd over looked it before also when I took wastegate off its not easily spotted as they are very small