After confirming my wideband is working and MS2 tune appears ok, I went back to basics again this weekend. Switched my coil packs around again and still had a very weak spark. Have decided to rule out component failure and have a brand new coil pack and yellow 8mm ignition leads on their way. Hopefully that will sort things out?

In the meantime I have fitted a spare cam cover on the car and got to work stripping the wrinkle finish off the scruffy one, ready to repaint. . .