Those with upgraded Fuel Pumps...

Never ahd any issues with my BBK 155 pump, as far as the fuel level gauge, nothing changed from stock. Has your mileage actually changed?

i have a 190lph engine works pump and it will run fine all the way to an empty tank.either your gauge is off,bad pump or your filter came loose when you installed the pump(that is the fuel pick-up)so when you get low on fuel it's not picking any gas up and starving the engine.

There is a bracket that holds the tubes together that support the pump. It is soldered to the tubes and is somewhat flimsy. Mine broke & allowed the fuel pump to move around. It could be that yours broke when you twisted & turned it to get the pump back it the tank.

I ended up drilling a hole through the bracket and putting a machine screw through it. I put a big washer & a self locking nut on the other side to clamp the tubes. The fix was better than new, something Ford should have done to begin with.

The other possibility is that the baffle that holds fuel around the pump pickup could have broken loose & shifted. It is nothing more that some sheet metal that sticks up an inch or so from the bottom of the tank. If it was damaged, dislocated or missing, fuel could move away from the pump pickup, depending on the movement of the car.