more questions!

is there any reason why my rev counter would be reading twice the real revs compared to my MJ on the lappy?

If its a smiths RVC tach, they do that, see HERE , John re-calibrated mine for the MGB.

I dont understand why they do it, on normal ignitions they get 1 pulse per ignition event, i.e. 2 per rev, an MJLJ creates 1 pulse per ignition event, same 2 per rev......

Is it just when connected to the megajolt or is it also when you connect it up to the EDIS module?

ive only tried it attached to the MJ as i thought the outputs were identical?

I think it depends on which type of gauge you've got - I know there were some issues with the older type ones...

here's the links to the smiths fitting instructions:

linky 'old' type

linky 'new' type

ah, its a new type,

i had followed that website right up until the bottom section, thanks for pointing out my stupidity