91 camaro 3.1 idles fine but almost dies

I have a 91 camaro RS 3.1 v6 I recently purchased. A lot of parts have been replaced on the engine. There is only one problem. When i press the accelerator, it seems as if it is going to die. if i let off and gradually give it gas it will rev up but at certin points it will start to bog down again. i replaced all the plugs and wires and the TPS(throttle position sensor) today. It still has the same problem. Also the fuel pump, filter, ECM, Prom chip, Distributor and air filter were replaced Could someone PLEASE tell me what is wrong with this vehicle. I am at my wits end. I am not getting any check engine lights either so i am really puzzled