Servo Vacum Pipe

[xxspudxx]

Where i have fitted my bias Pedal box, it obviously isng't servo assisted, so i was just planning on blanking it off in the inlet, but when running the car earlier, i put my finger over the hole to just blank it and when rev the car it would never idle back down, would idle really high, but if u left air back in the blanked part for a split second it would idle normally again.

So if i blank it is it going to make the car idle all over the place? if so what do i do?