HI,
AS above if your sure spark is consistent, then move on to fuelling, when the
engine is running have the co% checked as the car starts from cold and warms
to normal temp, to see if the co% is correct and if the ecu and sensors are all working as they should ie coolant temp sensor, thermo time switch, cold start valve
auxiliary air device, fuel pressure regulator,and pressure actuator, and the metering flap is not sticking, also check the fuel pump has 11.5volts
minimum,operating, and check all hoses to the turbo from the air box and from the turbo to engine,could go on compression test etc, hopes this helps.

Dave R.