the rs2000 16v uses batch firing, basically what it is is injectors 1&4 fire together and 2&3 fire together. lets say cylinder 1 is on induction so both injectors fire (4 fires to a closed valve) when 4 is on induction 1&4 fire again but this time 1 is to a closed valve. on WOT (wide open throttle) all injectors fire at the same time