TSI Tank Clean out

[Newkidontheblok]

so the TSI decided to start juddering at h`way speed, I thought was a faulty coil pack or plugs and went to change them with no luck, then I took her VW for a full diagnosis and they said I had dirty fuel in the tank oil had mixed with the fuel from a filling station, they recommended I remove the tank and clean it to start with. after taking this job on myself was surprised at what I found. I did clean it out good and proper but alas she still has the judder so my next step is de-carbon and perhaps new injectors as tried injector cleaners in the tank and no luck

If the pump is still good, and it ought to, it's been oiled, maybe there's a drop in pressure from oil contamination in the fuel filter. I don't know how you would check the pressures on those.
When the dealers apply injector cleaner, they apply it neat straight into the fuel lines.