I'm only guessing here so experimentation is in order. The viscosity of oil
thins out in higher temperatures (summer). So maybe the resistance of the
SU pistons, against rising, is less in summer heat. And when you are coming
to a stop, there may be a tendency for the floats to rise in the fuel
bowls, allowing more fuel to stream into the fuel bowls and this
temporarily increases the flow of fuel into the carbs. That extra fuel may
be putting some upward pressure on the needles.
Perhaps you need to experiment with thicker viscosity oil in the SU dampner
pots, so you get more resistance to piston rise in the SU carbs. Again,
just a guess. I would still clean up the carb linkage and check the
throttle shafts & plates for binding.
Fred - So.SF
>Author: Robert.Long@CSDInc.com
>Date: 8/13/2001 2:11 PM
>
>-----Original Message-----
>From: Hoon Kim [mailto:hoon@pixar.com] Sent: Monday, August 13, 2001
>12:26 PM To: datsun roadster mailist
>Subject: starting problems solved!
>
><snip>
>>> I noticed that when coming to a stop, almost always my
>>> idle rides really high (about 500 rev higher), and I have to tap
>my >> foot on the gas to have it come back down. Could this be caused
>by >> gunk, either around the pedal or the throttle cable?
>
>I seem to have the same problem on my 67.5 1600 with SUs. I have it
>idling nicely at 750 RPMs, but have to tap the pedal after I stop to
>get the RPMs back down. It seems to do this more in summer than other
>times of the year. I'm looking for suggestions too...
>
>Robert - 67.5 1600 - ABQ
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