Re: [DML] Cold Idle Problem - one more thing

["joekuchan" <josephkuchan@xxxxxxxxxxx>]

On a careful re-read of Bill's posting I think what he's saying is 
that as long as the total restriction presented by the throttles, 
idle speed motor, opened manifold screws, or what have you, is held 
constant, then for a given air flow vacuum will be the same. In other 
words, if the throttles are cracked open slightly AND the idle speed 
motor is able to compensate by closing a bit, then the vacuum will 
stay the same. This is true within the limits of the idle speed 
system. 

What I wanted to be clear about was that vacuum is the result of two 
things: air flow and a restriction. The restriction is required for 
the vacuum to be present.

I neither wrote nor discovered the laws of physics, but that is just 
how it is. That is why dashpots work, why carburetors work, why 
turbos in suck-through designs are more prone to drawing oil through 
the compressor seal when the air filter gets dirty, why free-flow 
exhausts are "good", etc.

If what Bill is saying is that it doesn't matter what the restriction 
is caused by, for an equal restriction at a given air flow the vacuum 
will be the same, then I agree. I just wanted to be clear on how that 
vacuum gets produced!

-Joe Kuchan

--- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@xxxx> 
wrote:
> 
> 
> The engine produces the same amount of vacuum whether it's idling 
off
> cracked throttle plates, opened manifold screws, or CIS. All three
> accomplish the same thing.
> 
> One thing cracked throttle plates will do that neither CIS nor the
> manifold screws will is open ported vacuum. On a stock DeLo setup 
that
> only affects charcoal canister purge.
> 
> Bill Robertson
> #5939
> 
> >--- In dmcnews@xxxxxxxxxxxxxxx, "Joseph Kuchan" <josephkuchan@xxxx>
> wrote:
> > 
> > You should start by readjusting the throttle to the proper 
position.
> You 
> > will never fix it if you make "masking" adjustments, although I 
know
> you did 
> > that just to get by with the intention of fixing it properly at 
this
> time. 
> > By turning the throttle adjusting screw you almost certainly 
reduced
> the 
> > amount of vacuum the engine produces. That can affect your 
braking,
> among 
> > other things, so start by getting that set properly.
> > 
> > Next have a look at the idle speed motor and its controls.
> >








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