Fuel Starved 2000 Ranger 4.0
My 2000 Ranger 4.0 (just purchased) has what seems to be a fuel starvation problem at specifics times. On grades where there is a bigger load for the engine, hot weather etc. The idle is perfect, and the sitting rev is smooth, so not injectors. Just replaced the fuel pump and filter, better but not cured. Should I test pressure on the rail and change out the mass air sensor?