Hi Folks,
After seven long years of looking, I've finally become the proud owner of a
shiny red TR3A. As you can imagine, I'm really enjoying working on it and
driving it around.
One of the things that has me stumped is the idle speed. It doesn't want
to idle below 900 rpm. A slight backing off on the idle screw(s) and the
revs drop immediately to zero and the engine dies. When driving around and
coming to a stop, there's a 50/50 chance that it will cut out on me. I can
prevent this by pulling out the choke, if I see the revs are dropping too
fast.
As an experiment, today I backed off the fast idle screw completely so that
pulling out the choke only enriches the mixture (and doesn't open up the
throttle valve slightly, as it would do normally). Driving around, I can
still prevent it cutting out by pulling out the choke. This indicates to
me that the whole problem is a lack of fuel at low revs.
Some background:
Replaced everything electrical, except the distributor.
Double checked the valve clearances.
Rebuilt the SU carbs using the major kit from Moss, and new needles. New
air cleaners.
The throttle shaft bushings do not appear to have excessive slop and
spraying carb cleaner around the shafts (and carb and manifold gaskets) has
no effect on the idle.
I'm loathe to pulling the carbs apart again as I have managed to get all
plugs with the nice brown/tan color.
BTW, the compression reading on a warm engine were all 175-180. Needless
to say I was ecstatic, but isn't this a bit higher than norm?
Regards, Adrian
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