Here are a couple of other experts comments
I think there is more than one problem here. The two combining make the symptom appear but they both need to be fixed. I know the battery is new but..
Hi Greg,the voltage at the battery reads 9.8 volts while being cranked over.
This is no good. Either the starter has way too high draw, there is a bad connection or the battery is junk, my vote is battery junk if we are guessing.
the fuel pump pressure reads 62 lbs. when I turn the key on and then again when I turn the key off. The fuel pump hums for the usual two seconds then shuts off , as soon as it shuts off the pressure drops to zero until I turn the key off or on again
also not good.
So let's put the two together, fuel pressure drops off to zero meaning it is going to take more than the usual prime to get it going. Battery drops off means slower crank and less voltage to the pump which results in lower volume in a case when you need max volume. The two systems need to have a thorough going over. Fuel system isolated to find the leak and battery/starting system isolated as to what is causing the voltage to drop to 9.8 under load. I was guessing battery because it starts with a battery charger, that charger is not putting out the amperage that the battery should be capable of but without a starter draw test that is just an educated guess.
This question goes all over the place!
I think I want to find out where we are at too.
I was under the impression that a few weeks ago that the vehicle would start and run, once it got started, for a whole day, and then not start the next morning.
Now it seems that it will start briefly (5-7 seconds), but then dies.
I also wanted to send the following PDF file along for you to look at. It shows how to troubleshoot the fuel pump electrical circuit. It also shows the my memory has not totally failed, as it has the part about the computer keeping the fuel pump relay energized if it receives pulses from the ignition system, while the engine is running.
Fuel Electrical Circuit Diagnosis
I sure wish I was there or could connect a GM class 2 scan tool to it can see what was happening.