Hi Rob,
Just a few comments:
1. Is the vacuum capsule on the dizzy working? Should retard the timing
when connected. Timing is to be set with the capsule connected. If not
spend 10 bucks on new elbows/ends for the vacuum lines, then re-adjust
timing. (do you have points or electronic ignition?)
2. set valves slightly loose -- .012" gap instead of .010". Change oil-
nice fresh 20W-50 is best.
3. Needle almost all the way down = TOO lean? My car runs (and passes
emissions with) the needle about 4 turns ccw from full rich. (5 1/2 turns
drops the needle) (I have the factory Cat and air pump, 49 state)
4. new needle: was it the same as the old one? Is the jet hole replaceable
in your carb? (It was not on my '79) Jet hole was worn, resulting in rich
mixture.
5. The richness you see may be a result of "lean misfires". That is, if
the cylinder fails to ignite the fuel because it is too lean, then you get
unburned gas and you fail for HC. (That's what you mean by rich, correct?)
Try it richer.
6. A Cat 'way back by the muffler may not be that effective, as the input
charge has to be hot for the reaction to take place. (That's why OEMs
mount them so close to the engine.)
7. I know you rebuilt it, but a leaking bypass valve induces air (and lean
burning). Think the referee would notice if you installed a blank gasket to
disable it?
While I don't have a pat answer for you, maybe the above points will get
you thinking....
Good Luck,
Atwell Haines
'79 Spitfire
Succasunna, NJ USA
At 09:01 AM 10/11/2001 -0700, rtgetzinger@scif.com wrote:
>This is on a '74 Calif Spit that is yet to pass smog. It now passes visual
>and functional but not the emissions. Here's the facts:
>Compression 1 to 4: 110, 115, 110, 110.
>Full EGR system-working properly, includes stock ex. manifold
>2 degrees btdc, 900 rpm idle, Runs very hot at this setting & cools down
>when retarded a bit. Indication of being lean?
>Rebuilt carbon canister, adjusted valves
>Rebuilt carb & bypass valve & new needle, needle screwed down until it almost
>drops off.
>At idle, with the air filter off, I use a screw driver to lift the carb
>piston/needle about 1/8 inch allowing more air, idle slows down. Indication
>of being lean?
>Smog test results: just a bit too rich at idle and at 2000 rpm
>
>Just put on a universal catalytic converter right in front of the muffler,
>only place it would fit without dragging on the ground. It is not stock on a
>'74 but the referee stated he'd overlook it, he's getting to know the car. I
>am hoping that the cat converter will burn up enough of the unburned fuel in
>the exhaust to get me lean enough at the exhaust outlet to pass.
>
>My question is, is there something I am missing, or is there an adjustment
>screw on a stromberg to lean it out or is the only adjustment the raising and
>lowering of the needle?
>
>Thanks
>Rob
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