I think you need to find out for certain what sort of sensor you have and what sort of signal it outputs. Is it definitely a Hall effect sensor? I would have thought that an MVR sensor was more likely.
how can i test to see if it is a mvr sensor?
mite be easier to just get a now one so we no what we have then somthing like this?
http://www.amazon.com/Inductive-Approach-Proximity-Sensor-Detection/dp/B004U4GCCW/ref=pd_sxp_grid_pt_1_0
but would be better in 5v