In article >,
says...
> then remove a spark plug and while
> grounding it to the engine using a rubber glove as an insulator, see if you
> get spark while someone else turns the key.


He probably wont get spark if the car cant tell when its on a
compression stroke. "compression sense timing"

Also a stock .040"-.060" gap isnt sufficient to determine if the
ignition system is weak.

This spark tester you can see the center electrode, this isnt good for
modern HEI ignition systems.
> http://images.amazon.com/images/P/B0...CLZZZZZZZ_.jpg

This spark tester you cannot see the center electrode, this is good for
modern HEI ignition systems.
> http://images.amazon.com/images/P/B0...CLZZZZZZZ_.jpg
If your ignition system cant jump this gap then you can be certain that
the ignition system is weak.

You use this tester with a short piece of rubber hose. Find a 3/8's
rubber hose about 3-4 inches long with an inner diameter that will fit
over the tip of a spark plug. The hose should be check with an ohm
meter. Since its black rubber it should have "carbon" in it. This will
conduct electricity and its resistance should be no greater than 10k
ohms or something... Push one end of it onto the cars spark plug (leave
the plug in the engine.) then clamp the other end of the hose with the
Spark Tester and attach the plug wire.

Doubt anyone followed that but thats the only way you can cheaply and
accurately gage the strength of the ignition system.