1.9TD engine cuts out when driving a few minutes but will idle and rev on the spot without problems

My 52 plate Superb has been refusing to start, I had the immobiliser disabled on the ECU and replaced the ECU relay located next to the ECU under the bonnet. I was getting a no communication error the car is now displaying no error codes.

The car now starts first time, I've left it idling without issue for over an hour and I've sat and revved it without any issues. As soon as I drive it, it goes for a few minutes and then cuts out. Once it has cut out it will not start again without the assistance of starter fluid. Once started again everything seems fine until I start driving.

Any advice much appreciated, it seem to be pointing to fuel starvation but I don't understand why this would only happen when I start driving.

Thanks in advance for any advice.