Astro Van running rough and no power after replacing the fuel pump?

I have a 2000 Chevy Astro that one morning didn't want to start. I thought I had run out of gas so I put some more but that didn't help. I checked to see if the fuel pump was making any noise and it was not so! because of the winter (snow) it set for about a year before I replaced the fuel pump then when I started it, it was running rough and has no power..not even enough power to move itself..it moves eventually and drives but so weak that even when I floor it, it cannot even reach 50 miles/Hr. the parts I replaced are: Spark plugs and wires, Mass airflow sensor, EGR valve, distributor cap and rotor, O2 sensors. PCV Valves. The tests I run are: Snap on says upstream rich that why I replaced the O2 sensors. When I try to plug the exhaust with my hand the exhaust pressure won't let me. When I push the pin in the valve on the fuel line, the fuel spits with enough pressure and the valve itself is not leaking any fuel.

Any ideas or suggestions?

Thank you very much!