hard to start when engine cold!

1995 jimmy 4.3 vortec-w 122k miles
replaced fuel filter ,no help
cold,ignition on,pump pres.55psi,drops to 50psi after5 mins and holds.
after about 10 start attempts, finally starts.
engine warm. idle, pump 56 psi.
quick acceleration test, 64 psi
pinch return fuel line test, 60 psi
what should i do?replace pump? replace central mfi? or both?
Thanks.