This may be a little long but my problem is a mystery to everybody, even the GM Dealer. 96 Burb 4X4 5.7L
We had a problem with it having loss of power on acceleration after filling up. We changed the fuel filter and checked the fuel and it was fine. It would run but for no reason it would act up again. It has progressively gotten worse and it gives me codes for o2 sesors. (Changed) then cat converters (changed) now I will list the many things changed.

fuel pump ac delco (now 3 times, after second time it worked for a week)
fuel pressure regulator
fuel filter 3x's
throttle position sensor (again, worked for about a week after changing)
egr valve
used seafoam
cat converters
o2 sensors (only front ones)

Has been to 3 mechanics and all have no clue. Last mech. was the Dealer and he is the one who said it was the fuel pump and we weren't getting good fuel volume. Now after the last fuel pump change it worked for 1 mile and quit. Now it won't start at all. Could this be a problem with my injectors? Or am I missing something. I know they are the poppet kind and I heard they are not good. I hate to give up on it but I am about to buy a Ford and drive (push) this one off a cliff. If anybody can help! I have become very familiar with this engine but I am an amateur.

check your fuel pressure at the motor , should be a port close to your distributor, it takes 60 psi to open the injectors, if you have that then look at fire those models are prone for thier bad dist caps, and rotor button corrading over. fire at the spark has to be a blue color if red , it will not start.

I apologize, I did replace the cap, rotor, plugs and wires. It was late when I posted last night, and I thought my list looked short. I will check the fuel pressure and I will also check the spark. If it is the injectors, could I clean the injectors or do I need to replace them?

Check for a dirty MAF sensor and vacuum leaks. Then check the IAC valve.

Had same problem with a friend of mine 1999 chevy suv, done same as you 2 new pumps still had problems, turns out that the plug connector on the wiring harness at the fuel pump was burnt, might check that wasn't getting good connection, he has since replaced it again . His pump was the high pressure pump. Connector plugged straight into the pump.hope this helps.

Thanks for the post. We had already replaced all the wiring inside. We finally figured it out last Friday. We dropped the tank again after reading another post on this forum. The instructions for the fuel pump tells you if you have a fuel pulsator, don't get rid of it. Replace the hose that connects the pump to the line. That is the wrong thing to do. Well, we got rid of it, used the clamps instead and put it back together. I guess our pulsator wasn't holding the hose properly and that is why we weren't getting the correct volume. That is also why it would fail at random times. We aren't having any problems now. I hope this helps somebody else with the same problem. Not sure why the directions from the dealer pump are wrong. Govt. Motors has severe problems. Thanks for everybody's help.