Ok, panic over! Last night I had managed to dislodge the hall sensor from the distributor housing and had the HT leads for cylinder 1 and 2 mixed up. I'd assumed it was 4-3-2-1, but is in fact 4-3-1-2. The idle and running is smoother now, even with a progressively more blowing exhaust!
It doesn't drip any oil onto the road so must have something there, but from any angle I try to see, I just cannot see what is there!
Old stuff.
New stuff.
Here are some photo's of last night efforts, you can see the distributor cap was in need of changing, although the contacts didn't look as bad as expected.
The rotor arm though had definitely seen better days, and really didn't want to come off! Hence parts of it broke in my attempts to remove it.
Loose hall sensor this morning, luckily all the wires appeared fine, and the connector looked quite healthy. I'll know where i'll look first though if any missfires occur in the future...
Phew, clipped back in.
Need to do the exhaust next, and rear light cluster for the MOT, then I can tackle the oily mess of the engine, hopefully a replacement rocker gasket will cure that - when it's clean it'll make it easier to spot any other leaks.
Thanks for the help and advice,
Tom.