Fuel pump again?

I changed the fuel pump in my 1998 Safari Van one month agao today.
(Original Symptoms) Van would go dead at different times at any speed anywhere. It would crank right back up and go till next time. Maybe a minute or perhaps a day or two later.
Did this for about four days and finally quit completely. NOTE: one time after it cranked I shook the key and it went dead immediately. Then cranked right back up again.
A good friend of mine is an ASE certified mechanic at a Chev. Dealership. He came to my house with his hand held analizer and found nothing in the codes or any electrical indications. We determined that by not hearing the fuel pump running that it was bad. I bought the new fuel pump from the dealer and he installed it.
It now has done exactly the same thing again with one little quirk in the chain of events.
After dying several times exactly as before I parked in in my driveway and the next morning it cranked up fine. When I got in the van to leave for work I purposely giggled the key and it went dead and has not cranked since.
You cannot hear the fuel pump at all as before.
Everything on the dash lights up as it always does and the starter turns the motor when I crank the vehicle and I get an accurate fuel reading.

Does anyone have any idea what is happening here.

I hope there is an answer here.
Mine did the same thing yesterday to the extent I had to have it towed.

Started a couple of days ago.

I replaced the pump about 3 months ago.

I found this. Would it apply possibly?
http://www.automotiveforums.com/vbulletin/showthread.php?p=2976907