why does my van stall? on 1999 GMC Savana 3500

When we took it to Autozone, the computer said that there was a short in the circuit to the fuel pump. We replaced the fuel pump and bought a new relay but the van kept doing the same thing. Once we got it started, it would die and would be hard to start or when we would drive it, it would die and not start or would take a few minutes to start. Also if the van was parked for maybe three days or so, there seemed to be less problems keeping it running. would run for the whole day without dying. But, if we turned it off and then tried to start it again, it would die.

Asked by for the 1999 GMC Savana 3500
If there is a short in the CIRCUIT for the fuel pump, the pump is not the problem, it is the wiring. GM Vans have had some issues with their fuel pump harnesses.
3 more answers
I have had bad trouble with the fuel pump relay..I would be driving and my 1998 GMC Savannah bus would just shut off..It is a small school bus converted into an ice cream truck for vending.I made no changes to any electrical etc..All I did was take out the seats in the small school bus.The problem was that the fuel pump relay would pop up..When your vehicle stalls or wont start open up the hood go to the box on the right hand side and push down your relays..It cost me over $700 to have my vehicle towed home from an event and only to be showed that that's why it wouldn't start.If I would drive over bumpy roads it seemed to happen too..I usually check them before I even leave, because it was no fun driving on a highway..and hear my bus shut off..When you push down on the relays you can actually feel it pop back in..I have had several problems with this bus..the aircondition went and no one can figure out why..etc etc
THERE WAS A TECHNICAL SERVICE BULLETIN issued(a soft recall where if you go thru a dealership they should inform you but they do not send out a full recall notice).the injector pump is mounted right to the engine block and will asborb heat and stop pumping hence stalling out, the best solution is not from gm but there is a aftermarket heat sinking product, you de mount the pump put the heat sinking on the block and then remount the pump to the heat sinking....some times you can continue to use the same pump... the cost is around 750$ for the retrofit kit....much better than the 2500$ which a dealership would charge as a non warranty repair
i have a 1999 gmc savana 3500 gas v8. i had the same problem with the van stalling and not starting right. I found a L shaped plug under the driver side door that connects to the transmission and there was a prong with a loose connection