My 99 Tahoe had a failing in-tank fuel pump. It howled, pressure was failing and it had over 180K on it. As a preventative measure I replaced the in-tank fuel pump. Truck ran great for 8 minutes, then lost pressure and died. Not wanting to pull the fuel tank and replace the fuel pump again at that point, I installed a "booster" pump inline to the existing fuel system by adding a high pressure fuel pump just before the fuel filter. I wired the second pump to a dash switch and prior to attempting to start the truck, I just turn on the power to pump #2. The new in-tank pump does not restrict the flow of fuel through it, and any attempt by the in-tank pump to move fuel simply helps the new external fuel pump pick up fuel and pressurize it. Fuel pressure at the fuel rail is back to factory standards (around 64 psi) and the truck runs like new. Does anyone see a problem with a setup like this until I can once again pull the fuel tank and replace the fuel pump again?