Thanks Pete. Yes so i just went out and rechecked all 4 plugs ..all 4 sparking.
Tommorow I will take the cold start line off at the manifold end as you suggest (I did check the mfi output to cold start with a spare line I have . I guess the line on the car could be blocked so I will do it properly as you told me to....
Will swap back to the original dirty fuel filter and see if it starts like it did previously.
Starting to lose interest in this "dream car" now haha
Thanks for your help.