Starting Issues - 1.8T

I recently had to have a replacement engine put into my 2005 A4 Cab - both engines where the BFB 1.8T version and the donor car was also a 2005 A4 Cab. Since the replacement I've have difficulty starting the car and over the last few months I've replaced all the temperature sensors, the thermostat, the spark plugs, the cam sensor and the crank sensor - all faults that have been picked by VAGCOM.

The issue seems to be that the engine turns over but eventually becomes flooded.

Can anyone recommend any other areas to look at? It's becoming increasing frustrating as the car runs fine when it eventually starts.

Many thanks, Rob