After the van throwing a conrod through the block we've had the engine replaced with one from a breakers, 83k on it alledgedly? some parts were needed from the old engine e.g turbo and fuel pump.It starts fine and sounds very smooth until you start accelerating(use this term loosely as its like a slug on vallium!) when you accelerate it starts to get very noisey sounding more like an old transit!! and it's well down on the power the previous engine had(150k on the clock) we've also notice a slight leak on the fuel pump.Ive read somewhere that there are a couple of different makes of pump for this engine, and that if you fit a different make from that of the original it was fitted with it can cause the symptoms above?? can anyone shed any light on this???