> Ob. LBC tech question: OK, I drove the Europa once or twice last week
> with no problem. Yesterday afternoon and today I've had no choice (time
> for the annual "rebuilding of the starter" for the Plymouth).
>
> It's *acting* like there's a fuel problem, either starvation or way too
> rich (bucking, hard to keep it at idle, etc.) I don't think it's
> starvation, since I just put new filters on and purged the tank. It
> feels as though it's running right when I accelerate, but at constant
> speed I can feel some jerking, bucking motions. The ammeter will
> fluctuate just *slightly* with each buck, but not enough to make me
> suspect electrics -- I think that's from the drop in RPMs.
Oddly enough my daily driver Mazda has similar problems. Here are my
conclusions for my car (Hitachi carb, which is a weber clone):
There is a small leak around the throttle shaft, and a ridge worn into
the area where the throat contacts the flap actuated by the throttle. The
combination creates an exceedingly lean mixture when throttle is held just
above idle. The car bucks, forcing my foot slightly off the throttle, forcing
me forward, forcing my foot slightly on throttle, etc. If I make an effort
to hold the throttle dead even, I get the characteristic semi-backfiring
sound of an engine running lean. My solution? Never drive with partial
throttle :-). If I cared about the car I would replace the throttle shaft
seals, and contemplate sanding out the ridge in the throat. Other causes:
There are a number of holes drilled into the side of the throat, which are
meant to enrichen the mixture in a calibrated way as you open the throttle.
If any/all of these are clogged, you would undoubtedly have similar problems.
Any of this being useful is of course predicated on your weber being similar
to my Mazda's weber clone. I don't remember which weber this thing is a clone
of, but it is amazingly similar to the webers on my Maserati (proving that
it could show up on a performance car). But I think all webers work on
similar principles.
Joe
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