FWIW, too lean increases HC also. Ideally, you want a
stoichiometric correct mixture (14.7 F/A) in the
idle/part throttle positions.
Deceleration creates HC due to high manifold vacuum
sucking exhaust back into the cylinder, diluting the
mixture to the point of borderline misfiring. A
throttle return solenoid to slow it's closing will
help this.
Retarding the ignition some will reduce HC also since
it raises exhaust temperature.
GM
----- Original Message -----
> Sounds like you are running rich. A tuneup may
help. We don't have emissions
> tests in my area so I can't say definitely what
will work, but I have a few
> suggestions.
>
> Try the tuneup first. Make sure all emissions
system components are working.
> If that doesn't work, you could try a modern
replacement carb. It wouldn't be
> difficult to add catalytic converters, but you
would probably have to devise
> some form of insulation so the heat they generate
doesn't melt the floor.
>
> Some states exempt cars over a certain age from
emissions tests. You may want
> to check to see if there is an antique vehicle
class you could register under.
>
> Scott Isensee
>
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