I have just rebuilt and installed a set of Stromberg CD150 carbs on our Mk1
Vitesse, and although they have made a great difference to the car's
performance, there are still a couple things that don't seem right.
Hopefully someone out there can help.
The main problem is that I can't get the choke to function
properly. I synchronized the starter bars as described in the workshop
manual, by raising them until they both just touched the base of the air
valve and then tightened the linkage. I then returned the bars to the
fully off position and tightened the choke cable. After tuning and
balancing the carbs with the Gunson Colortune and Carbalancer I set the gap
between the choke cam and the adjusting screw on the throttle to the
specified gap of 1.5mm.
The problem is that set up like this, the cold engine will fire
with the choke out, but will only run if you immediately dab on the
accelerator. It will then stall as soon as the accelerator is released. I
have partially fixed the problem by reducing the gap between the cam and
the screw on the throttle stop from 1.5mm to practically zero. The choke
now functions if it is only partially pulled out, but pulling beyond a
certain point causes the engine to falter and die, rather than race. It
seems to me that the relationship between the starter bar and the amount of
throttle opening is still incorrect. What have I done wrong? Is it just
that the cam is worn? Should the starter bar be fully closed when the
choke cable is pushed fully home, or should it be just touching the base of
the air valve? Are there any other possible causes?
The other possible problem is that using the Colortune, if the revs
are slowly raised from idle, the flame goes yellow before returning to
blue. According to the diagnostic chart, this means the metering needle is
worn. However, I have fitted new needles and jets (taking care to get the
needle base flush with the air valve and to centre the jets), so there must
be another reason. Any ideas?
Thanks in advance, Pat Edwards.
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