check f19 for fuel pump according to haynes 20 amp fuse if all oki [this is not on wiring diagram but on list of fuses in haynes manual, infact no fuses come near the fuel system except FV6 which is prob engine bay big fuse nxt to passenger headlight]
then go on to fuel pump relay
black box nxt to the abs system
one is for fuel pump and the other is for the ecu
both are purple and have same part numbers
u could try swapping them over to see if the fuel rail pressurises
if that dont work then put the ignition on and get your volt meter on the fuel pump connector
to get to that lift up the rear seats and under the carpet and in line with drivers seats is a black pastic cover, get that off and you should see a blue insulated cable, unplug it from fuel pump and test for volts, if you get volts then look at fuel pump
it is quite rare that they fail as the publicity is around the vectra c high pressure fuel pumps
the good news is that they cost around 25% new to that of a vectra c fuel pump - about 50 - 60 quid