Your lift pump provides fuel to the injection pump. The injection pump will pull fuel but that is not what it is designed for, it was made to push fuel, so when you throttle up, it cannot keep up with itself, starves for fuel, and will cavitate in time, requiring a rebuild or replacement. Your lift pump should be "clacking" as soon as the key is turned to run, feeding fuel to the injection pump. If you don't hear the "clacking", you either have a power issue or need a new fuel lift pump.