[Healeys] FW: Timing light query

Mon Mar 18 07:56:06 MDT 2019

Simon,Some timing light instructions indicate that the clamp that goes on the #1 spark plug lead must be oriented with a specific side of the clamp facing the plug. This orientation is probably based on assuming that the car has a specific ground polarity. For example negative ground. Since you said your car runs OKish, I  would suggest using the car battery & connect the positive lead of the timing light to a good source of positive voltage. Connect the negative lead of the timing light to a good source of negative voltage. One of these two can be a good ground connection such as the engine, not a painted surface. I do not recall which way you have the battery hooked up so will not suggest where to connect your leads. Finally, clamp the spark plug lead around the #1 plug wire &  with the engine running pull the trigger on the timing light see if the light flashes. Some timing lights has two brightness settings. Read the instructions to determine if yours does. If yes, try them both. If it is not flashing, try reversing the direction the clamp that is attached to the spark plug wire & check for the light flashing again. Finally, I also assume a 123 distributor is not a "MSD" multiple spark discharge type of electronic ignition device.Good luck.Gary

-----Original Message-----
From: simon.lachlan <simon.lachlan at alexarevel.plus.com>

I started the timing light saga by asking if I could run my lamp off an independent 12v supply. And the answer was “yes”. (A moot point anyhow as my spare battery has died).At the time of asking I said something like “I’ve got a Mac timing light and it works fine…”. And it did, last time I used it! Now, it’s  about as much use as a chocolate teapot. One little glimmer and then nothing. I shouldn’t have tempted fate……It’s a decent looking thing and I somehow doubt that it’s just given up the ghost while sitting in its case.I don’t abuse the tool……I connect it and disconnect according to its rather pedantic instructions and I keep it secure in its rigid plastic case. It’s not been bashed around though I came close this afternoon.Thing is….when I had the car tuned for its Webers on the rolling road about 2 years ago, the guy tried two lights, one of them a Snap-on, before he could get a reading. That got me wondering about lamps in general and then, this afternoon, about my car in particular. And I recalled that these lights seem to be quite fussy in what they like by way of spark plug leads. I see that cheapo lights can be had for under £20.00, say $27.00, on eBay. I could just about run to that, but it would be pretty silly if that didn’t work either.(Our two daily drivers are diesels so I can’t try the lamp out on them).What else can I say? Car runs OKish. (Timing is off!!). It has a 123Ignition distributor which uses carbon(?) leads. Not copper anyhow. And it has a Sports coil with about 7,000 miles on it. Nothing in there looks dodgy, but does it ever?Anybody had this sort of thing happen? Any ideas?Simon

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