D3 Intermittent Start Fault

[woodpoleman]

I have a 2005 D3 3.0 TDI Quattro with an intermittent fault since May. Car will start but sometimes there's a lag between turning the key and starter kicking in and when out and about after a couple of stops will not start. Turn the key hear relays clicking but starter does not engage. Leave it a while (can be 30 mins - 2 hours) it'll start again. My garage has replaced starter ecu, ignition switch, starter motor. I've replaced engine coolant sensor and starter relays. Audi re-coded ecu, replaced and coded new battery. Audi had the car for two weeks started 4/5 times each day but never drove it so fault never occurred. Any help and ideas will be gratefully received.