Robert & Hoon,
This is one thing to pay attention to. I've had POs (never me) who have
put on incorrect springs on the carbs. If they are too strong they will
speed up the ware on the throttle shafts/bushings. Make sure that
everything is clean and there isn't any leakage. You can spray carb
cleaner on the outside of the shafts while the car is running. If things
are tight there shouldn't be any change in RPMs. If there is you have
leaky shafts. A couple of things that will prevent decent runnng of
your car are warn out throttle shafts and distributor.
Dana
Robert.Long@CSDInc.com wrote:
> I'm currently using Automatic Transmission Fluid in the dampner pots
>
> Does anyone have a pic of the return springs on their SUs, I'm curious
> if mine are stock or not.
>
> Robert- 67.5 1600 - Abq
>
> -----Original Message-----
> From: Fred_Katz@ci.sf.ca.us [mailto:Fred_Katz@ci.sf.ca.us]
> Sent: Monday, August 13, 2001 2:28 PM
> To: datsun-roadsters@autox.team.net; Robert.Long@CSDInc.com
> Subject: Re[2]: starting problems solved!
>
>
> 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
>
--
Dana Nojima, Ph.D.
HYSEQ, Inc.
Cell Biology Group
675 Almanor Ave.
Sunnyvale, CA 94086
(408) 746-4567
noji@sbh.com
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