Rough Idle when engine is cold

I could use some help from my fellow VW drivers. My 1974 Super Beetle
has a rebuilt engine which I installed in 1996. The engine is stock
with all hoses and egr connected and working. The car passed smog every
2 years. The problem I am having is that when I start the car in the
morning there is hardly an idle. The engine runs very rough even when
I give it gas (pushing down on the accelerator pedal). The throttle
lever is on the highest step of the stepped cam. As the engine warms up
and the choke opens the engine runs smoother and the idle gets
stronger. I am guessing that the problem is just a carburetor adjusted
incorrectly. Now I know when an engine is cold it needs gas, not air.
With the choke plate closed the ratio of air/fuel is mostly fuel. When
the choke plate is completely open (vertical) the ratio of air/fuel is
now mostly air (or should be). Can my problem be the bypass opened too
much and the mixture not enough?

I have tried to adjust the carburetor myself but I don't know if I am
doing it right. I turn in the mixture screw until it bottoms and then
back it out 3 turns. But as soon as the choke is vertical the engine
dies. I have to turn out the mixture screw 5 or 6 turrns just to get an
idle. I then turn out the mixture screw until I get the fastest idle on
my tach. I turn it in until the rpms drop 30 or so and then I start
turning in the bypass screw ( which I left flush with the screw
opening). The idle speed starts to drop as I turn in the bypass screw.
When I get 900 rpm I stop.

Is my way of adjusting the carburetor ok? Am I getting a lean mixture
or a rich mixture or can I tell without bringing the car to a smog shop
and letting a tech hook it up to his machine and measure the hydrocarbon
and nitrous oxides emissiona? I did put a piece of cardboard over the
carburetor and even with the opening almost completely covered the
engine runs perfectly. It only dies when I cover the carburetor
completely. I will bring the car to the local VW shop in a few weeks or
so but I would like to resolve the poor idle in the morning problem
first.

Thanks for any input

azazel scratch wrote:
>
> I could use some help from my fellow VW drivers. My 1974 Super Beetle
> has a rebuilt engine which I installed in 1996. The engine is stock
> with all hoses and egr connected and working. The car passed smog every
> 2 years. The problem I am having is that when I start the car in the
> morning there is hardly an idle. The engine runs very rough even when
> I give it gas (pushing down on the accelerator pedal). The throttle
> lever is on the highest step of the stepped cam. As the engine warms up
> and the choke opens the engine runs smoother and the idle gets
> stronger.

<SNIP>

I wonder if you have *too much* choke when stone cold.
Start the engine when cold.
Manually rotate the stepped cam so that the choke opens somewhat.
See if that smooths the idle.
If it *does*, loosen the 3 screws on the choke element (rt side)
and turn ceramic element to adjust.

Speedy Jim
http://www.nls.net/mp/volks/