Ford Repair: fuel, direct correlation, fuel pump

Question
i have an 87 f150 4.9 liter 4x4.after starting it soon runs out of gas ,the fuel pump runs when you turn the key on.it also turns on if you over advance the timing.it has a new relay.what tells it to turn on when low on fuel?i had to run a hot wire to it to get it to stay running.any help would be appreciated.
                            thank you
                               kevin

Answer
I'm not sure what kind of answer to give you. There is no direct correlation between the timing and the fuel pump. The fuel pump should only be on for a few seconds when you turn the key on, then after the engine is running the pump will stay on. Probably best to check for codes before going any further. Any fault in the fuel pump circuit should give a code. Have you checked the fuel pressure? Could be something preventing the injectors from firing.