1999 Chevy S-10 S-10 Wont Start

Ok, where do I start. Some history, and its not a sob story either. My wife and I have 1 son, then our nephew and his wife were put in prison and we now have 4 extra children to feed, diaper, etc for the next 18 years! (All kids are under 3). So the first car I promised to my 17 year since he was 5 years old never materialized due to money issues. So this past summer he went and worked on a farm to earn money but the farmer offered him a 1999 S10 V6 4.3l Vin X in trade for the labor. He swore that it ran and only needed a new ECM. To prove it he cranked it using gasoline sprayed into the intake and it ran fine as long as he sprayed gasoline. My son worked hard, got the truck, I towed it home and now its in my back yard and wont run, and I dont have any way to pay to have it fixed. I have tried the following myself, but I am a computer guy not a car guy.

1. I replaced the ECM with a new one. It was tested and programmed to the actual VIN on the truck. I was told it had to be programmed to work with the passlock system. I did the procedures and the security light is OFF.

2. I replaced the fuel pump. It does run for about 2-3 seconds when I turn the key to ON and then stops. I have pulled the fuel lines off and ran it and from the actual pump the fuel shoots EVERYWHERE. I disconnected the fuel filter and fuel came out of it on the engine side of the filter. THen I disconnected the metal fuel lines at the intake and primed the pump and gas sprayed everywhere.

3. I replaced the PCV valve, not sure what for, but someone suggested it.

4. I took the Mass Airflow Sensor and used a whole can of MAF cleaner on it and its so clean I would eat off it!

What happens now? When you put the key into the ignition and turn the key it tries to start. Oil pressure comes up to 40. All dash lights go off except check engine light and low fuel (low fuel because I dont want to fill the tank and then drain it again) The tank has about 5 gallons in it though. It turns over and over but no start.
I thought it might be the spark and getting to the plugs on this engine is a big problem (shame on GM) so I got a spray bottle and had my son turn it over while I sprayed fuel into the intake. The truck cranked and ran as long as I sprayed fuel into the intake.

Someone suggested the injectors werent pulsing? Dont know what that is. I thought well, it cranked with fuel in the intake so it has to mean the injectors are working. But to be sure I disconnected the big black plug that apparently provided power to the injectors and figured. Well with no power they wont work and the truck wont run. So we tried to run it again. IT RAN. So now Im not sure if the injectors may ACTUALLY be bad or if its electrical, etc.

People have suggested testing this sensor and that voltage. But they all assume I know what the hell Im doing. WRONG. Im just trying stuff with the old Trial and Error method. I cant test the pressure as someone suggested because I dont have a fuel pressure gauge. I went and bought a multimeter. But dont know what to test and how to test it.

Some people said look at the injector rail. I dont see it. Im afraid to take off the intake and then break something else.

So this is long enough for now. I will leave the question with one last comment. If you help me please realize that Im an idiot and you will probably have to tell me not only how to test something, but where it is and what it looks like too!

I felt so bad for my son that I pawned the title to our surburban to get the ECM and fuel pump which were $600 together. So please please help. I think somebody out there knows whats wrong because Ive asked several "mechanics" to help and all they want to do is offer to buy it from me. So apparently they know a "Mechanics Secret" or that its an easy fix. And I dont.


Thanks and God Bless,
Don

P.S> I am donating for the question and will donate more as I can. I know we are all in tough times and if someone is willing to help me figure this out, and has patience I will reward them best I can. So the small initial donation will increase if we can get this figured out.