Yeah, it would be good if someone knew the problem straight up.. but unfortunately that rarely the case !

Sorry about this dyno sheet, as it is a scan of a scan.. i don't have the original print out here at the moment. I am just wondering if a faulty injector cause be the problem ? I am going to have a good going over of the wiring of it tonight I think.

Is it normal for the Afr to rise like it does at the end there ? as it has already made most of its power at the time the afr starts to rise.