1990 coupe deville 4.5l hesitation

hey i have a 1990 cadi coupe deville with the 4.5l in it. when i am accelarting my car hesitates and seems like its down on power a lot, when at crusing it is fine. i have replaced my fuel filter,wires,cap,rotor,plugs. had my injectors cleaned and have no clue what else to look at? any one have any ideas or answers? i am at a loss with this. thanks Ray

Welcome to AF, checking fuel pressure is next. Does it feel like a misfire or it just lacks power?

it feels more like a miss, but its very slughish. what knid of pressure should have?

Throttle body efi correct?, if so 12-13 psi.