Ok boys and girls... Think I've this one put to bed now.. I'd gotten a replacement TPS and tried that. Didnt make a drop of difference.

So got thinking, pulled the air temp sensor out of the inlet manifold, thing turned out to be covered in black crap, cleaned it off with some carb cleaner and put it back in. started the car and still not running right.

chanced my arm and put the diode back in that line, started first time, idle dropped down to a nice level. seems to be perfect now except still a tiny bit rich but hopefully a drive will sort that out.

Cheers for all the help people!