Coolant temp sensor will be faulty, you have probably got the black one fitted, go to VW and order the green one.
If you can get it scanned for DTC's you might see the code in either engine or instrument. If not check the data from cold.
The coolant sensor gives a signal to the ECU to tell it how hot or cold the engine is and in turn will give it more fuel on start up.
Some times they will cause the car not to start if this happens just disconnect and it will start.
Any problems or you would like me to run a test let me know.
Chris