mpyrol

I am leaking gas from the top of my fuel tank. I need to get the fuel out so I can drop the tank. The fill line runs into the side of the tank so I cant just pull it there. It's impossible to feed a siphon thru. My thought is to use the pump to pump it thru the pressure port on the fuel rail. I'll pull the relay and short the terminals and run it out. Any caveats to doing this? These pumps aren't really designed for volume and I am not sure if the pump power is tied into any of the control modules. I am also worried about running pump for long duration and burning up pump.

tech2

the fuel pump is designed to run for years. the fuel in the tank cools the pump. disconnect the fuel line at the fuel rail or any other easily accessible location. not sure what year uplander you have... for a 05 all you need to do to run the fuel pump is pull the fuel pump relay and jump power to the correct relay pin

there are 4 pins
one has battery voltage all the time...jump that one to the fuel pump pin
one has grd
one goes to the pcm
one goes the fuel pump

mpyrol

So I attached fuel pressure gauge hose to fuel rail, pulled the relay from the socket and jumped the 12v to supply side of the pump. it took about 30 minutes to pump 17 gallons from tank. I didn't pull the schrader valve so it probably took longer than it could have. I checked the service manual and this wire goes straight to the pump. It grounds at one of the factory grounding locations listed. The leak turned out to be the fuel pump outlet tube. I purchased a new acdelco pump without the sending unit. It swapped out perfectly. I was concerned about the fill tube coming from the side of tank and spilling a lot of gas but there is a check valve there that is very effective at keeping the fuel in the tank. You don't have to worry about spillage other than what is in the fill tube and the curved line at the front of the tank.