Weak spark possible short?

[12jslater]

The old girl had been sitting about a month and had a slight misfire before sitting, now the misfire is AWFUL at idle, yet sometimes clears up and the engine revs absolutely fine.

So I replaced the points and now she won't start, I've tried several condensers plus one known good one. Lt wires have been checked and all connections are spot on.

There is sparking between the points yet when using a multimeter there is continuity between the points evem when open.

I'm baffled by it.
Does anyone have a clue as to what this could be?

[philthehill]

Have you got the insulating fibre washer under the spring blade of the points?

[12jslater]

I have, that was the first thing I've checked (happened before)

[myoldjalopy]

And an insulating washer on top of the spring blade as well, to prevent the LT wire shorting out the points?
Bit of a long shot but I once had a non-starter traced to the contact plate screw washer having fallen into the dizzy (after fitting new points) and shorting the points. As soon as I saw it and pulled it out the car fired up straight away.