Hesitation, surging and crap mpg.

[Lawrence]

Just tested for a good spark on all cylinders.  Pulled each HT lead off in turn, stuck a spare plug in it and held against the head.  Got a white/blue spark but not a 'fat blue' spark as they describe in Haynes.  Oddly though, it started up exactly the same with only three plugs connected (any three) as it does with four.  Took the reg/rec off and checked with a meter, all appeared to be ok; lowest 660, highest 685 with the others spread out between.  Also tried it with the reg/rec disconnected and it still misses occasionally at 4k in neutral so it's not that.

What next?  Anyone got a spare CDI I can borrow to test?