misfire/stutering under load 20vt

AGGGHHH,  so i have finally got my scirocco 20vt conversion completed but for the last 2 weeks now its been missfireing/stuttering under load and i cannot find the cause, its an agu lump with s3 injectors and a k04-001 turbo running qpeng plug and play, i have been permanently emailing ben at qpeng but still not coming to a conclusion whats happening, so far i have done the following, checked wires vacum hoses (hundreds of times) new spark plugs, new coil packs, new uprated fuel pump, crank shaft sensor,

if anyone knows any thing else what it could be or what i could check would be a massive help 
im starting to loose the enthusiasm with it now and tempted to get rid of it :-(

Does the rocco use a lift pump in the tank?  had similar problems with a standard gti. After everything was changed and a lot of head scratching ended up being the poxy little lift pump..

im not sure to be honest, it has the main pump just under the drivers rear wheel which i changed and uprated, i take it the lift pumps in the tank? ill have a look if i get chance this weekend, thanks

you checked the injectors mine was running crap and mrc said that the injectors were to blame