The Logic Level Converters are these https://www.sparkfun.com/products/8745
I had buzzed out the connections high and low side, so I am pretty confident they are behaving normally.
The module is powered from the 5v bus on the arduino, however I have just checked the 3v3 max current draw an its 50mA max from the Arduino, however the specs show it can draw up to 69mA in active sensor mode. That also doesn't take into account the current drawn by the Level Converters either.
Looks like I will have to sort out a breadboard psu and a 3v3 arduino so I can stop using those level converters and clean up the wiring.
I suspect this project needs to be paused until the above are sourced. Thanks for all your help so far, I will keep everyone updated.