Pumpe Deuse engines require an in-tank pump to provide fuel to the unit injectors. 

Great Upgrade for ALH/AHU/1Z Cars

Adding a lift pump to VE engine cars takes work away from the rotary pump since fuel is provided under low pressure (7.25 PSI rated) to the injection pump whenever the ignition is on. This helps cold starting, makes the engine run smoother at low speeds, and provides more fuel at high load, especially helpful in modified cars. Installation requires custom wiring with a relay and power source. These items are available in the install kit. The pump will fit in the tank of Mk4 and Mk3 cars, although the Mk3 may require some work to make sure the fuel gauge reads accurately.