So it's all back together, heads on, timed up etc.
car started and ran / idled lovely .... Then I drove it to the petrol station 1 mile away and it was Ok, kangaroo'd once it twice but pretty civilised. Driving back from the petrol station and the car was kangaroo'ing like mad. Pulled back into the garage , came up with a fault code on bank 2 Cam Sensor. Bought a new one. Replaced it, exactly the same ! Nissan advised me that my idea of bank 2 was there bank one (I say bank 2 is #2-4-6, they say bank 2 is #1-3-5?). Anyway, bought the sensor for bank 1 and still kangaroo'ing and would idle stable.
Stripped it apart and the retard who timed it after refitting the heads had got it 1 tooth out ?!?! Luckily nothing was damaged so it went back together with the correct timing aaaaand....
Cranks much smoother and more rhythmic... But lost spark AND fuel again ?!?! WTF
Checked every plug / earth and there fine, no fault codes so the Cam Sensor fault I was getting was down to bank 2 signal not reading what it should be in relation to the Crank and bank 1.
Took it to Nissan today, they have no idea. It's getting a ignition signal but won't try as fire, not imobiliser either. So iv left the car with them. Any advice will go a long way tho guys so feel free to jump in