Yes the ECU trips the relay negativly and so if you earth the relay the pump should run continuously, if not then it's NOT an ECU problem. You should also find the amal valve will not click when the ignition is switched on, as this to is powered from the fuel pump relay as well as the ISCV.

The earth from the relay should go to pin 28.

Edit: Those pics also confirm what we thought earlier that it does have a remapped chip.

Martin