Lack of boost can not be caused by pump timing if the engine runs fine.It could be either a wastegate problem on the turbo the k14/k14 wastegates like to get seized up due to carbon or the inj pump could be underfueling the engine.You need to find out what the fueling specs are when the pump was setup.Find out what size of head was put in that pump either 9,10,11 or 12mm.Did your other TDI-m pump have the aneroid on top of it?Ask the builder why they did not put an aneroid on your pump?How much did you pay for that pump if you don't mind me asking?I've never seen such a bare bones pump before,Looks way too primative IMO.
are you using just a 1.5d pump on a tdi? if so that's your problem