Re: Distributor Questions-TIMING LIGHT USED!!!

[jlandry@domain.elided (John A. Landry)]

The aliens commander decided MikeIIDC@domain.elided would make a perfect
specimen for dissection, and he yelled...

>Also, I have a noticeably missing spark on my #8, #1, and #4 wires.
>Would this be due to a weak coil?  Bad cap?  Actually, when the recent

Mike,

A couple of things come to mind since you have now eliminated just about
everything else (regarding the non-sparking plug wires)...

Have you pulled the spark plugs on the offending cylinders to see what they
look like?  When were they replaced last?

I'm thinking along these lines... if the spark plug was somehow bad
(possibly excessively high internal resistance or because of burned
electrodes with excessive gap), then possibly the ignition system can't
develop enough voltage to fire such a plug.  If a spark couldn't be created
at the plug tip to complete the secondary ignition circuit, then it follows
that no voltage would be flowing through the plug wire.  If no voltage
flows through the plug wire, then there's nothing for the magnetic pickup
of the timing light to detect.  Make sense?

You might also try disconnecting one of the suspect plug wires while the
engine is idling to see if there's a change in idle quality or rpm.  If the
spark plug (and cylinder in general) are doing their job, then killing that
cylinder (by disconnecting the spark plug wire) will cause a decrease in
engine idle rpm and an increase in roughness of idle quality.

If you detect no change in such a test, than something is definitely wrong
with the cylinder.  It could simply be the spark plug isn't working... or
it could be something much worse that would require further investigation.
Try that test on all cylinders you suspect are not firing.  Wear dry gloves
(the heavier the better) and pull the wires by the boot so as to reduce the
risk of shock.  With a stock ignition system in good condition, the chance
of shock is rather minimal.  You gotta be careful around the MSD and Crane
systems though... especially when running large plug gaps (high voltage
being developed).  In that case, the electricity is just looking for an
excuse to nab you!

Another thing to try is maybe disconnect a suspect wire at idle, and then
ground it to some convenient place on the engine block.  Then, with that
wire still grounded and the engine idling, see if the timing light detects
the voltage which should definitely be flowing through the wire in that
condition.  If it doesn't then, then I'd try a different timing light!

Keep us posted,

John L.
-------------------------------------------------------------------------- 
jlandry AT halcyon DOT com      | 
Conservative Libertarian        |  "The road to  tyranny, we must never
Life Member of the NRA          |   forget, begins with the destruction
WA Arms Collectors              |   of the truth."
Commercial Helicopter - Inst.   |                     William J. Clinton
http://www.halcyon.com/jlandry/ |    10-15-95, speech at the Univ. of CT