Subject: Re: ignition question
Author: Patrick Hayes
Date: Apr 16, 2005, 11:34 AM
Post ID: 1718713357
Ted Ward wrote:
| Yeah, it was a suggestion by Mark Etheridge to hook the plug wire directly to the distrubutor input nut instead and manually crank the motor over to statically time it. While doing this I noticed the light flashes twice when the points open and when they close. if I crank the engine with the starter I see two flashes in quick succession every time the light flashes intead of just one. |
Well I thought that's what you said. (Someone else reported that it was
two flashes per distributor cycle. That would be correct, but not two
flashes per engine or crankshaft cycle.)
I think we have a semantic argument here. There are two kinds of timing
lights. The first, oldest, simplest light is simply a 12v bulb with a
single lead and a pointed probe. Set this up on the distributor/coil
low voltage lead and it will light and stay lit as long as the points
are open. As soon as the points touch, the electrons prefer an easier
route to the ground and the bulb goes out. Using this lamp, you set
your crankshaft at the desired idle advance position. Install the light
by connecting the power clip to the downstream or distributor side of
the coil and pushing the pointed probe against any grounded engine
metal. Turn the ignition key to ON. Turn the distributor body
clockwise until the lamp is out. That means the point lifting lobe is
sitting at the bottom of one of the two valley recesses in the
distributor cam. Now slowly turn the distributor body counterclockwise.
At the instant the points are lifted off of contact, the flowing
electricity is suddenly diverted to the test lamp circuit and the bulb
lights up. Stop. Turn the key off. Tighten the distributor clamp.
I think what you are using is an electronic hi-intensity strobe light.
It is intended solely for the 25,000 volt hi-intensity secondary
circuit. It is designed to sense changes in electricity flow in the
wires and does this by inductive sensing. If you hook this lamp to the
12v coil lead as you have suggested, it just might "sense" the increase
in electricity flow at point closing and THEN also the cessation of
electricity flow at point opening and would indeed give flashes on both
sides of the point contacting and opening.
Mark doesn't give erroneous advice. When he told you to connect your
"timing light" he was likely referring to the low voltage probe style
light. Meanwhile you've hooked up an "inductive strobe" not intended
for those wires at all.
Patrick Hayes
Fremont CA