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