:S Was the larger 1.9 TDi (140bhp) engine ever fitted to the MK1 Fabia and then tuned down (eg VRS ) ? and if so how do you tell which engine it is

nope

:S Was the larger 1.9 TDi (140bhp) engine ever fitted to the MK1 Fabia and then tuned down (eg VRS ) ? and if so how do you tell which engine it is

The later VRS engine coded BLT usually sticks out around 145BHP as standard. Not sure why exactly as it's very similar to the older ASZ engine, but with improved emissions.

BLT is just factory remapped.

and the 140bhp TDI engine seen recently is actually a 2 litre 16v, not a 1.9 8v.