Hi FIRST DONT USE EASY START OR YOU WILL NEED IT FOREVER
I had this sort of problem on my horsebox
D reg 0813
On  these engines next to the thermostat there is a single wire for the temperature sender 
And next to that two wires connected to another little sender unit this is the cold start sensor it has a supply to one side and if cold power runs through and onto a solenoid on side of injector pump...excess fuel for cold start 
Check wiring on it or you can just join these two wires together so it just uses excess fuel every start 
This will not cause any problems unlike 
THE DREADED EASY START😞😞😞
Hope this helps Craig...
                
 Craig
                
 January 2013