So yeah i think it's sorted. Failing lambda sensor. Picked up one from the motor factors this morning and all appears to be well. Emmision are down now anyway and staying down. Oil from last engine failure must have killed it. Still kicks out the odd bit of black smoke if reved hard bit i think thats just all the soot in the exhaust which should clear. Done the ignition timing again just to be sure and set the idle. Idle switch needed adjusted too. Will monitor it again from cold tomorrow.
As for that black wire spliced into the red wire that goes to hall sensor it went upto a female spade near the coil but hasn't been connected to anything in a long time by the looks of it so just removed and re-soldered it back to how it should be and shrink wrapped it.
Hopefully that's it then.
