On TT Swaps
When converting your NA to a TT, there are two optional routes one must take in regards to fuel pump control.
Install a TT pump, but continue to use an NA FPCU. You must also socket the ECU and install an EPROM which is programmed for a swap, as an NA ECU doesn't have the fuel/ignition maps for forced induction, and a TT ECU would try to control the three-speed FPCU which doesn't exist/doesn't have wiring. A TT ECU also tries to control wastegate actuators and the two-speed cooling fan, both of which don't exist on NA models.
The NA FPCU will run the TT FPCU at higher voltage than a TT FPCU would under the same conditions, but most agree this is without ill-effects on the fuel pump, and any excess fuel is dealt with by the fuel pressure regulator.
Install a TT pump, TT FPCU, TT ECU, and TT body harness (or run a wire from the ECU to the FPCU harness to supply voltage for the third speed).
In general, you should not install a TT ECU in an NA without running the wiring for it and using a TT FPCU, as a TT ECU will try to utilize the third fuel pump speed, which doesn't exist. To a TT FPCU, "speed 1" is 6V, "speed 2" is 7V, and "speed 3" is battery voltage. To an NA FPCU, "speed 1" is 8V, "speed 2" is battery voltage, and "speed 3" is "who are you? what? where am I?"
Taken from here: http://z32.wikispaces.com/Fuel+Pump+Control+Unit