i have a 2.0 2014 superb .ruff idling  when hot and cold ,i have new bosh high pressure pump 4 new injectors ,diesel filter lift pump working well .no fault codes ,

new fuel temperature sensor . if i disconnect temperature  tick over nice but brings no fault code ,put wire back on sensor ,runs ruff .

any one help please 

Not every fault will result in a stored fault code, especially with sensors where the failed state still returns a plausible value.

 

I'd be inclined to have a diesel injection specialist look at it, or at least a competent indie mechanic who's familiar with VAG diesel engines.