Chevrolet Repair: v-6 hessitation, throttle position sensor, fuel pressure regulator

Question
I have an 88 chevy 1/2 ton 2WD with a 4.3 v-6. It hessitates and stumbles when you accelerate. It acts like the mixture is not getting enough fuel. I have replaced the O2 sensor, fuel injectors, plugs and wires. Do you have any suggestions? Thanks.
Mark

Answer
Hi Mark,
I would TEST the fuel pressure, and then TEST the throttle position sensor.
Low fuel pressure during the problem could be the pump, but could also be the filter, or the fuel pressure regulator.
Test that stuff before you go buying new ones because someone else "Thinks" it is the injectors, etc.
There are also a couple other sensors that could be telling the ecm to not send the proper amount of fuel.
Van