Major shake, idle an mpg problem

[Iyeoman]

Hi I have a 2008 gt TDI 170.
Had head gasket changed with belt an ever since car has vibrated under load an had bad idle.
No codes or lights on dash
Had wiring an 20 hours diag on it, new manifold, fuel pump in tank, tandem pump, injector wiring loom, new injector oring kits,new everything.
Had timing checked an done but no matter what is done it still shakes in acceleration, mpg is really really bad an has lack of power.
Seems to be over fueling really badly. No codes for injectors but is really getting annoying as nobody has any clues who looks at it.
Anybody got any ideas what it could be?
Thank you

 

[diece]

Do you have VCDS ? If yes you may start as checking some injections value, air incoming, per cylinder value... start here.
That could be lot of things
Bad MAF
Bad EGR
Bad Injector Unit
Bad connection injector (unlikely cause you change the wiring)
Bad injector seal (unlikely like you replace them)

May the work wasn't done correctly ? How could you evaluate that ? Like the anti collision adjustment for injector ?