Paul Heuer wrote:
>Steve,
>I've had the same battle with my Alpine running the twin downdraught
>Zeniths. Mine is definitely related to heat exapnsion rates of the throttle
>plate and butterfly. I still haven't solved it completely. Next step it to
>recon another throttle plate to eliminate the troublesome unit. Could your
>problem be related to heat rather than engine on/off?
>
>On the Zeniths the extra return spring worked for a while as the car warmed
>up, but it still stuck sometimes when the car was at full operating temp.
>
>No vac secondaries on the Zeniths ;-) so I can't help on the second point.
>Cheers,
>Paul.
>
>
Hello Paul:
I did get a reply that my secondary operation is normal. As to the
throttle plates staying open without a return spring when the motor is
on, it doesn't seem to be heat related. With the motor on, cool or hot,
without the extra carb. return spring, the plates stay open and keep the
idle about 400 RPM above normal idle. Watching them, as soon as the
engine is turned off, they snap shut immediately. Turn the motor on
again and rev it once or twice, they stay open more than you want. With
the extra return spring, they do close to the proper idle position with
the engine at idle. It's weird becuase when you close the plates using
the throttle lever on the car with the motor on, there's a good deal of
resistance, almost like something is rubbing on something else. With the
motor off, there's no resistance and the plates close smoothly without
the extra spring.
Now that I think of it, I wonder if I have my electric choke adjusted
too far open. I'm going to turn it closer to the closed position and see
what happens.
Thanks.
Steve Sage
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