I've recently fitted a T34 and -31 Collins actuator to my Saph.

When it comes on boost, it pulls as it should to begin with, then starts to cough and splutter.
Does it just need set up, or is there something else i should be looking at??
It ran spot on before!!
Been told d/v needs uprated to run stage3, is this true??

Engine bay spec prior to fitting T34:
4" Mongoose, Greens, 3 Bar Map Sensor, Stage 2/3 Chip, Group 'A' Fuel Pump, RS500 Cooler, K&N, NGK's, Bailey Dump Valve, Motorsport Leads. Running 22psi.

Any info greatly appreciated Guys.