I seem to be curing the mis fire in stages....bit by bit it is getting better !!!!
I have cured the Crank sensor loose connection and the engine is a lot smoother, still lumpy on tick over and at 3200 rpm.
Had a new front section exhaust fitted (which was blowing badly) and the engine is much better (and quieter), plenty of power although still lumpy on tick over and at about 3200 rpm. Would damaged Lambda sensors cuase this lumpyness as I have not changed these yet but both cats on the old exhaust were totally shot?. I am using the original sensors.
Plugs and lead are brand new and removing each injector lead in turn shows all cylinders are firing, so I am guessing a fuelling issue.
Any help/experience would be appreciated before throwing it at my local emporium for diagnostics.
Alun