PEUGEOT 307 HDI D-TURBO?

Why does my 2003 peugeot 307 hdi's d-turbo's turbo come in late? Whilst going through the gears the turbo is delayed, so the car is sluggish, then decides to come in around 3000rpm.(instead of 2000rpm) Also when on tick over is doesn't seem to be idleing correct, like a juddering?