03 yukon denali wont stay on

[TimWolve]

I am new here so i am sorry if this is the wrong area, this is kinda an emergency, My fiancees 03 yukon Denali was working fine few weeks ago..
we got a full tank of gas at the local cenex then went our way to the next town, however while in town the pedals were feeling a little stiff, mostly the accelerator, then one the way home the vault meter was starting to drop while the dash lights were getting dim, then it started to feel like it was stalling out a little then the vault meter dropped down even more and then the truck just died, we guided to the side of the road where someone had to jump the truck, then it worked again however it was having a rough idle, we made it about ten miles, lights were pretty dim, vault meter was still low.. then the truck just died again.. tryed jumping and nothing.. So we had to pull it back home..

each time we tryed to start it, it would start a few moments then die.. or when it would try to start, it would start to back fire into the air box.

we took the alternator and battery out to get tested and both passed.. so we were told to try hitting the gas tank with a rubber mallet and then turn the key to aux a few times and try starting it.. sometimes this will start a weak fuel pump.. we did this and the truck did start for a few minutes this time.. then i turned it off, started it up again and it went back to back firing into the air box..

then a friend of my fiancees who worked on fuel pumps came to listen and the pump sounded as if it was barely kicking in.. so we assumed the pump failed and he changed it for us.. however after changing the pump and driving it around the block.. however he stepped out of the truck for a moment and just as he open the door the truck just died.. and after that he could could not get it started.. it had to get pulled back to the shop again..

he did find a fair amount of water in the tank which was removed.. however upon changing the fuel pump, the truck did start as if nothing was wrong but as soon as he drove a block, the thing just died..

we are in the process of moving.. this thing is becoming more of a burden rather then a useful SUV..

any tips, tricks or any cases related to this to help get this thing running again would be greatly appreciated

its Low miles, 6.0 motor, the check engine light is not on and i connected a simple code reader with no DTC codes.
and now the fuel gauge says theres no fuel when right after the new pump was put in, it sead it had half a tank.. the low fuel light is even kicking on.

 

[about20ninj45]

I am new here so i am sorry if this is the wrong area, this is kinda an emergency, My fiancees 03 yukon Denali was working fine few weeks ago..
we got a full tank of gas at the local cenex then went our way to the next town, however while in town the pedals were feeling a little stiff, mostly the accelerator, then one the way home the vault meter was starting to drop while the dash lights were getting dim, then it started to feel like it was stalling out a little then the vault meter dropped down even more and then the truck just died, we guided to the side of the road where someone had to jump the truck, then it worked again however it was having a rough idle, we made it about ten miles, lights were pretty dim, vault meter was still low.. then the truck just died again.. tryed jumping and nothing.. So we had to pull it back home..

each time we tryed to start it, it would start a few moments then die.. or when it would try to start, it would start to back fire into the air box.

we took the alternator and battery out to get tested and both passed.. so we were told to try hitting the gas tank with a rubber mallet and then turn the key to aux a few times and try starting it.. sometimes this will start a weak fuel pump.. we did this and the truck did start for a few minutes this time.. then i turned it off, started it up again and it went back to back firing into the air box..

then a friend of my fiancees who worked on fuel pumps came to listen and the pump sounded as if it was barely kicking in.. so we assumed the pump failed and he changed it for us.. however after changing the pump and driving it around the block.. however he stepped out of the truck for a moment and just as he open the door the truck just died.. and after that he could could not get it started.. it had to get pulled back to the shop again..

he did find a fair amount of water in the tank which was removed.. however upon changing the fuel pump, the truck did start as if nothing was wrong but as soon as he drove a block, the thing just died..

we are in the process of moving.. this thing is becoming more of a burden rather then a useful SUV..

any tips, tricks or any cases related to this to help get this thing running again would be greatly appreciated

its Low miles, 6.0 motor, the check engine light is not on and i connected a simple code reader with no DTC codes.
and now the fuel gauge says theres no fuel when right after the new pump was put in, it sead it had half a tank.. the low fuel light is even kicking on.

If its a fuel issue, i would suggest teplacing the entire sending unit, and check for clogged injectors and or tune up. There is float valve in the tank, and if it is installed incorrectly( rheostat) , would cause the fuel reading issues. The issues could also be in the fuel lines. .