Well thank you for all your help ,
Did all the things you suggested, nothing, so sat back and thought about it a few years ago I changed the plugs on a motorbike ,
Run for a while then stopped went over every thing, changed the plugs, bingo, sorted
So I did this on the 6 changed all the plugs bingo running a treat now, so what happens to the plug when it goes tits up and is there any way of finding g wich plug it was
Cheers pink, thanks for your help