Dave:
I am still struck by the fact that only the number one cylinder
is having issues.
1. What are you setting your point gap to? Have you tried
increasing the gap a bit? I am thinking that perhaps you dizzy has a
flat lobe for the number one cylinder, and so the points are getting
opened enough to fire the number one spark plug.
2. Are you using any sort of electronic ignition? A pertronix
perhaps? Something that uses little magnets to fire each plug? one of
the magnets might be weak resulting in intermittent firing of the number
one plug.
3. Are your valves opening on the number one cylinder? Could you
have a flat lobe or misadjusted rocker on that cylinder so that the
compression is low or the cylinder is not drawing in enough air/fuel?
As I recall you have swapped the wires, plugs, and dizzy cap,
and swapped rotors for the dizzy.
4. Is your dizzy shaft worn? Can you wiggle the dizzy rotor from
side to side? If so, then the cam that activates the points may be
moving enough to avoid opening the points to fire the number one plug.
5. Are you certain that drive gear (in the block under the
dizzy) is in correctly? The slot in the top of the dizzy drive gear is
not symmetric, and if you get it in backwards the dizzy will not seat
fully, and your dizzy drive shaft can wobble. Try having a friend crank
the car while you watch the dizzy rotor (cap off). Does the rotor
wobble?
Cheers,
Vance
-----Original Message-----
From: Dave Murray [mailto:murr32@shaw.ca]
Sent: Friday, June 30, 2006 9:49 AM
To: Navarrette, Vance; 6pack@autox.team.net
Subject: RE: Timing issue
Vance
<snip>
What are you setting your plug gaps to?
[Dave]I have tried 0.025", 0.030", and 0.035" - no discernible
difference.
Which coil are you using? Have you tried a different coil?
[Dave] I have tried a standard coil, a Lucas Sport coil, and a Crane
PS40
coil - no discernible difference.
I am thinking that the issue may be that the number one cylinder
is simply a tad more difficult to fire (leaner mixture, colder cylinder,
or whatever) and you are showing a marginal ignition that simply happens
to show up on the number one cylinder. There may be nothing wrong with
the number one cylinder, rather there is something wrong overall, and
number one is merely the first cylinder to show the symptoms.
What year is your car, and what type of coil are you running?
For instance, you might be running an unballasted coil in a year that
has a ballast wire, and so your coil is running at 6 volts rather than
12. Etc. Just some random thoughts...
[Dave] Car is 1973. See coil options utilized above. I believe this
vehicle
has a ballast wire, Coil voltage drops from 12V to 8V when coil -ve
terminal
grounded. I have not tried bypassing the ballast wire.
Vance
|