on a vro type fuel pump,there is no vacumn signal at the tank fitting at the bottom of the pump.there is a pulsing coming from the hose from the block.if you feed gas to the punp manually it will push it to the carbs.but it will not draw any.i checked for leaks in the supply hose and bulb.seems good.is any of the electrical for the fuel or is it for the oil.im thinking the pump is bad-very expensive,so id like to be sure.thanks