why don't I have fuel pressure?

I test the power it was good so i just replace the fuel pump but still don't hear the pump running. The van did like to stall hot or cold before and then one day it didn't started I look at it didn't hear the pump then so the van sat for a couple of days and then it just started. We drove it for a couple days then it wouldn't start again. did all the test thought it was the pump but with new pump still not hearing the pump.I do have a new fuel filter in it that was the first thing I changed when it stalled the first couple of times. Any suggestions you have that I can try please e-mail me back. Thank You Levi