well it seems i stumbled across the problem....
the cam/crank sensor controls spark/ignition timing....the sensor needs to sit in the correct location on the exhaust cam...the only way to get the sensor fully onto the cam is to have it in the correct position so you cant really go wrong, it only fits on one way
the inlet cam does not have this part however....if you tried to fit it on the inlet cam you would find it would go in any on way and would still spin the sensor hence providing a spark...at a totally random time i hasen to add
so.....
it all becomes clear when i find not one but two inlet cams on the car and no sign of an exhaust cam..ahem
one of the original cams had marks on the lobe so i ordered a replaement one (second hand), it seems i was either sent the wrong one, fitted the scored one or ordered the wrong one, either way i have fitted the wrong one as neither cam has a keyway bit fot the sensor to locate into and unless im mistaken this means the ignition timing could be so far out its no wonder it wont fire up eh?