On the limited info available it's sounding like a blocked fuel filter or other impediment in the line of supply, or possibly a dicky fuel pump that isn't meeting demand in a certain rpm range. At 100k Km one might expect it to have gone off song. A DashHawk will give you rail pressures that you could compare with a normally operating MPS6.
A less likely possibility is sucking air into the line somewhere, if the fuel line has been damaged underneath or in the engine bay. Might be worth checking for damage, pinching and/or leaks.
CP_e Standback & PNP; CP_e 3" SS Downpipe; Corksport FMIC with Top-mount K&N filter & OEM Ram CAI; Turbosmart BOV; Dashhawk; Prosport Boost Guage; JBR solid shift bushes; DBA 4000 Wiper-Slot front rotors; Hawk Ferro-Carbon HPS Street front brake pads (@ 69,000km); Sumitomo HTRZIII's in 225/45 x 18