It was the coil!

[Matt Tomkins]

oh god, what a day - great day yesterday at beaulieu autojumble - got nothing on the list but still spent lots of money.
exhaust started to blow a bit on the way there, i considered buying a full new system for £40, but i thought to myself 'oh, it's fine, bit of firegum at some point...' - an hour from oxford she started to sound like a spitfire on take off (well, in my mind anyway) as the downpipe had slid out of the silencer box (welds broken). got her to oxford and a friend welded it up beautifully for me - no blow at all now and a great noise on overrun.
Heading home from oxford ahead of the Chiltern Hills rally today, she died completely and suddenly - managed to coast to a petrol station where i found the points had closed up and worn the heel out completely (despite being only a couple of weeks old). Replaced them, still no spark. regapped them, still nothing. replaced the condenser, still nothing. checked earths, all good. checked switching to coil, all good. checked power to coil - also good. jammed the king lead against the block and span over - nothing. (by this point, battery going flat and some kind soul offered me a jump start which helped eliminate the tiny flicker of doubt that it could be insufficent power from a duff battery. With a duff coil diagnosed, i called the AA - who came out an hour and a half later, drove me home to collect a spare, and drove me back where upon fitting, she started on the button. Finally got home at 1.30 am, thoroughly knackered and with a show this morning (and mistys ignition system (known to be working, i also took this back to mavis with me) to rebuild before the show!)

Moral of the story; always carry spares; you can never have too many spares! and, most importantly, IT CAN BE THE COIL!

[bmcecosse]

Which is why you should always carry a SPARE in the car! I do!! Can you put a meter on the coil and give us the resistance readings? A spare 'known working well' dizzy should be carried too -saves time faffing about with points etc at side of road - just swap the dizzy.

[JOWETTJAVELIN]

How old was this coil, because the old genuine Lucas/Unipart ones rarely give trouble.

[bmcecosse]

I forgot to ask that - new coils are often not correctly specified (most are sold for 'ballast' ignition systems), and are poorly made. The points could of course have been the death of the coil - I doubt they were completely closed - just very tiny gap. Running like that means the coil is 'connected' far longer between sparks - and will get hot........especially if it is a ballast coil! But I would dearly like to see the resistance readings from this 'failed' coil.

[katy]

i found the points had closed up and worn the heel out completely (despite being only a couple of weeks old).

Did you put a smear of grease on the cam?