Pulling my hair out

Mechanical injection, nice! So simple in theory. A friend has an all aluminum hemi, altered wheel base car with it. He says once you get the stacks sync’ed its gets pretty snappy. I’m not sure how much fuel “reserve” pressure it has. Say it dead hooks. The motor is dragged down, which slows the fuel pump. The pressure could drop and create a stumble. Don’t know much about mechanical injection.