[clarkey1984]

Absolutely top notch advice canis, although I used the main feed in pipe as couldn't seem to spot a return, although I do vaguely remember reading that t4s don't have a return to tank which might be why, I also used a switch in the wire as it made things easier to control.

It's also fair to assume that the intermittent misfire I was getting is fuel pump related, as despite draining in this way putting the pump under more load than it would normally be, I was getting about 20 seconds worth of pumping before the note changed and was accompanied with some wonderful grumbling noises, a bit like when a submersible is running out of fluid to pump, plus loads of bubbles, killing the power for a couple of seconds and then resuming cleared it for another 20 or so seconds, it did this from when I started at about half a tank until I finished leaving it just on the red, glad to know I've found the cause, albeit in a bit of an unorthodox way.