4 LV-EZ1 sensors and 1 uno

Hi,

I am looking for help connecting four LV-EZ1 sensors in parallel to a single Uno. I have each getting power from the 5v pin on Uno, each grounded to Uno and each going to a different analog pin (all connected with wire; no resistors or capacitors or anything -- if I need these please let me know), but only one sensor gives accurate readings -- the others are frozen at 6 in. or so. Is this a lack of adequate power, or do I need to connect things differently?

Thanks!