this might be a stupid question. why does TBI (and most FI) have a fuel return line? Is it to keep the fuel pump from cycling on and off? Or is it simular to a hydraulic regulator that has a drain to tank? Most fuel regulators I see in summit or Jegs don't have a return line, is this a different design? I couldn't find an answer on howstuffworks.com Also what controls the fuel pump? is there a pressure switch somewhere, or is it determined by amp draw on the pump? thanks in advance.