Which model of 156 is this? V6, JTD, Tspark or selespeed?
Which pump have you shorted out?
Have you had the fault codes read yet.
Smakys first ideas when he saw the thread title was low fuel or crank sensor, but he did say that not knowing which model 156 it is means that all the guys above are just guessing and they are obsessed by the fuel cut off switch.