Finally got a few minutes to finish this off
Tidied everything up, replaced the front scuttle, put the wipers back (been doing some work getting them to work better), started him up and went for a spin.
He used to just tear up hills from low revs, but when the misfire arrived, this was the worst place, up hill in low revs. Any hard acceleration started the misfire, but from low revs on an incline was not good at all.
Got to a hill, and eased my foot down to accelerate up it, from 1,800 rpm. He took off like a scalded cat, so problem solved
I did have the power to the tach fix coming from the main relay in the MS, so I suppose that's what caused it - who knows, he may have been having a bad day.
Tacho is working ok now, little jump now and then, but to be quite honest, it hasn't worked for so long now, I really can't remember if it did that before
Thanks for all your help, especially Dave
![Smile :)](./images/smilies/icon_smile.gif)