> Once I do get my electical problems resoved, I'm back to tuning.
> It now runs rougher than when I started smoothing it out! Sounds
> like a gallop cadence...
>
> I'm assuming this is primarily caused by bad timing,
IMO, that's unlikely to be caused by bad ignition timing. Could be other
ignition problems, like one or two cylinders getting a weak spark, but
(again IMO) other causes are more likely.
> although the
> the static light timing seems correct. (BTW, setting the timing
> mark 3/8" left of the pointer means, I assume, left from the
> driver's perspective?
Nope. Timing should be slightly before TDC, which means the mark would be
slightly to the right of the pointer from the driver's point of view.
> The only references I can find to adjusting the vacuum advance on
> the distributor says " move one click of the vernier to advance 2
> degrees".
Not sure what reference that is, but it's wrong. A single click of the
vernier is a tiny amount (in fact, there's a good deal more play in the
mechanism than that). There are tic marks on the barrel of the vacuum
advance, each one of those marks represents 2 degrees.
> Between the DPO and moreso the DCO, it's been spun to
> both ends of its excursion, and now sits at some random spot in
> between... how do I calibrate this to start at some known point
> of advance/retard?
You posted before that moving the vernier didn't make any difference in the
timing ... you need to fix that problem first. Then you can chose any
position on the vernier that you like, set the timing at that point, and
then use the vernier marks as a relative change from the point you set.
Personally, I like to move the vernier to two marks retarded from the center
mark and set the timing to TDC (mark matches pointer). Then move the
vernier to the center mark to get the factory-recommended initial timing.
Then use the "road test" method outlined in the factory manual to fine-tune
the timing from there. I'm a little conservative though, so I find the
point where it will just barely knock when fully warm and with heavy
throttle at low rpm, then back off a degree or two.
One other comment, it might be due to wear in my distributor, but it's
rather hard to move the advance with just the vernier nut. So when I'm
advancing the timing, I alternate pulling outwards on the vacuum capsule
with turning the nut, so that it's my pulling on the capsule that actually
moves it. Then when I have the nut where I want it, I slide the capsule
back in as far as it will go, as a reference point.
Randall
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