No fuel,89 cherokee

Just picked up this 89 jeep cherokee 4.0,auto 4wd, cranks but wont start,except with starter fluid. Put in cps , ground was off fuel pump reattached,checked auto shut off switch? drivers fender is working ,checked fuel relay,clicking. new pump in it,got another pump,both work when hot wired, had pump running when it was out of car but it seems like everytime i put it in tank it doesnt pump. not getting any pressure at shreddar valve. Checked at the fuel pressure wiring harness buy pump and was only getting 6 volts,thinking computer,but not sure, any help comments feedback would be appreciated, set me in the right direction?!