Thanks to everyone who let me take over Thursdays Digest to work through my
carb. problems. I was swapping out an air valve that had a "bad" adjusting
screw in the damper tube for an air valve with a good one (moved good needle
from bad to good valve). I wondered if this was good practice.
As it turns out, and I am embarassed to admit it, the #2 Bosch plug had a
broken insulator: I put my timing light on each plug wire in turn and found
this out. This was causing the faulty idle and bad running. Now I know that
we go Valves-Dwell-Timing-Carb as the standard order for rooting out
problems, and I had followed this to the letter. I can only assume that,
after playing with the carbs, the insulator let go. I replaced the Bosch
non-resistor plugs (made in India) for NGK non-resistors. Since I bypassed
the ballast wire and put in a Sport coil, I run my plugs at .040 thou. My
car now purrs like a kitten. At 900RPM I don't have a single hiccup or
uneveness; the car just ticks at idle and produces a nice, smooth feel at
speed. Oh Joy!
I learned a couple of things. First, never assume that something you worked
on didn't go awry by coincidence or maliciousness. Also, you can swap out
the air valves in the Z/S carbs, but do consider doing this in pairs, though
I did not and my car works just fine. You can remove the adjusting
screw/spider washer in the damper tube of the Z/S. If you are patient, you
can remove the ENTIRE damper tube from the air valve body (NOT a standard
practice) and may be the better trick for moving a "good" damper tube into
your existing air valve: it is an interference fit only. Remember to free up
these adjusting screws every so often so that they don't freeze like one of
mine did.
Thanks again,
John
johnw@wrq.com
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