O7 2.0 tdi A4 cabriolet cranks but won't start!

[maggotrunner]

It died the other day AA man said it was relays behind fuse panel numbers 373 so changed them was alright for a couple of days and won't start again no engine management light coming on.
cheers

[Sveneng]

I think relay 614 controls the fuel pump and ECU. If it turns but won't fire and the engine management light isn't illuminated this could be your culprit. The AA man could have easily freed it if it was sticking when he replaced the other one, hence why it worked for a couple of days.

[Crasher]

You should start with a fault code read.