So to recap, the symptoms are rough running and unburnt fuel.

Fuel is going into the cylinder but not igniting:
No spark
Weak spark
Timing wrong so spark firing at wrong interval
Weak compression

If all the above is fine:
Too much fuel due to air leak causing the ECU to over compensate
Or faulty injectors/seals

Could be a combination of any of the above.

Alternatively there is a problem with the ECU or a problem with the communication between the ECU and engine/sensors.

 

Stinks of fuel so assume fuel is going through but not being burnt, slightly blackened plugs and have been told verbally that 3 of the 4 arent sparking correctly after some testing. Vacuum leaks have been checked where possible, turbo actuator checked, new spark plugs, Map, MAF and lambda sensors voltage tested.

Obviously some of this is verbal confirmation etc so its hard to know the extent of testing etc.

 

Would timing be out due to belt position following rebuild? If so will this have caused any damage?

 

If it's had a rebuild obviously it's not been screwed together with holes in pistons etc. That car is running on 3 they won't run on 1 they will run on 2 well sort of very little wrong with that car I'm pretty sure an hour would diagnose it.
Firing order.
3 4
1 2
That's on the coil and leads to corresponding plugs on engine.
Yes if belt was on wrong it wouldn't run right obviously

 

Anyone close enough to GL19 to have a look with me or worse case if i go mad and buy it anyone around DT7 as that is where i am based.