Hi Stu thanks for the response, ive replied in red below.
Originally Posted by
Stu @ M Developments
If this is happening under more than standard boost, this standard gap is a bad start.
The issue is not with the plug gap as it happens even when not under load/boost when reving sat in neutral. i had a bigger gap on the old plugs and tried new ones with standard and issues the same.
Set to what?
Check distributor shaft end float too. theer should be zero.
checked, no float.
Set to what?
Have you also tried new CPS and PPS?
Not sure on the gaps but the car is currently with Jano at Oddkidd Creations, he's checked all the ignition side but with no luck on curing it.
Im waiting for him to send the head off for leak testing now as i think it could be related to that, although the cars been sat there some time now 
Been told today hopefully by the weekend so will sit tight and see.
Originally Posted by
costina
As Stu as said plug gaps are the starting point gap at 0.6mm and try.
Might be worth doing a leakdown test and a comp test.
Good luck.
Paul
Thanks mate, Comp test came back fine. leak down test will hopefully be done by this saturday, but currently out of my hands.
Originally Posted by
IainRS1700T
Fuel filter? Fuel pump? Start with the basics, maybe you've got some muck in there if old kit?
Cant see it being that mate. uprated bosch pump with msd wiring kit. and filters not that old. also the fact the missfire has surfaced since fitting a 2nd hand head and a new crank sensor means its gotta be one of those imo.
Wonder if the new crank sensors faulty? still to try a different one.