Thanks tony,did reply a week or so ago but it seems to have disappeared into cyberspace.
Fitted a new cam sensor which made no difference.Suspected injector problem so fitted 2 recon. ones.The 2 I replaced looked original. If anything it seemed worse.The guy I normally go to came back off holiday[or I would have taken it to him sooner] so managed to get it to him.Turns out it just needed the injectors recoding.He did say that if the cam sensor was faulty it wouldn't have run at all.