Where is fuel pump located? on 1991 Chevrolet G Series Van (G20)

I have replaced the fuel filter but my van is bogging down on the hills.

drop your fuel tank and its on the top of tank with fuel sender. the pump is repl with the whole sending unit approx 100.00 for delco pump
2 answers
Pump is inside fuel tank. Have systems test prior to doing any work.
Fuel press. and scan test. Can drive with press. guage hooked up to
see if psi. drops below acceptable range. while"on the hills".