Thanks for that. The only cheap and easy things a friend of mine mentioned (different friend) is to "wind up the turbo" (not sure what he means but may look into it), blank EGR and remap (that one isnt cheap but already done).
I have exactly that same issue, mine is a manual btw. It's just so dead up to around 2k, I still there is more to investigate because sometimes it kicks in at 1600-1700, sometimes not til 2000 (which in my mind shouldn't be possible as it's electronic code governing that), and also when it does kick in, it isn't always a smooth delivery. Sometimes there is a very feint feeling of blips/hesitation as it pulls from 2k-3k. Its very very feint though but might mean something else going on. The MPG when I first drove it home was low 30s, maybe even 33 or 34 I can't remember, but I was very happy with it. Since then I got it remapped, it definitely has more grunt after 2k revs but now delivers 22-24mpg at best. So something isn't quite right, I have jobs to do yet including a service so all the basics need ruling out first, and another clean of the MAF or maybe replace.
I have been working on gearbox selector yoke for several months so the centre console was out and I had a nice hole which meant every puddle I drove through gave me a wet groin, and not from enjoyment I can tell you.
Noisy it was too, so I was trying to keep the revs down and that obviously made it very sluggish. But even with that closed up now, I like to drive at low revs generally in any vehicle (to save pennies on fuel as well as just have a more relaxed drive!). I only raise the revs to 3k plus when really needed for a rare overtake of a lorry or tractor. So that definitely makes matters worse given the TD5 just manages to hold speed below 2k revs, forget acceleration! (in mine anyway!)
I have finished working on the gearbox, gear changes are 100 times better now (two box oil changes too). Still not quite perfect, but I think the new clutch will help that. I am sure it's got a SMF in it and I think that makes the combination of the low performance with my driving style a recipe for a sluggish machine. But even if I really give it some, it's the slowest manual disco I have ever been in and I have been in quite a few, and my mate must have owned ten of the damn things and even his old basher green laner goes better, not been serviced in about a decade!
I don't know what a vgt is, but definitely curious! Do you mean a variable turbo? Someone once mentioned that to me before but it's mega money I think?