Sean,

Few things, first you need to make sure whats in your tank....

Your pump pressure it not good in my book, and you should see around 4.5v, now that could be down to a few things, either you haven't challenged the pump correctly or you have a leak.

Here is an example of a good and bad leakage



I wouldn't eliminate your injectors at all, your capture is not very clear, but if you don't know what a good decay rate is how do you know yours is ok


"Car displays fault code P2339 - knock sensor 4 above threshold (neat seing as it only has 1)"

This code has been flagged because the delivery fuel is inaccurate. The system will listen to combustion noise through the knock sensor. your injectors need to be tested.....

HTH

Darren