Re: Cold help

["David Teitelbaum" <jtrealty@xxxx>]

The main reason is that the screws are brass and therefore soft.
Overtightening them will distort them and cause them to groove where
they seat. You could also possibly strip the threads. You are only
trying to stop a very low air pressure so there really is no need to
"gorilla" them tight. Actually only 1 has to be closed. If it is still
in the correct position it is the one with a slot in the head, the
other 2 are "balancing" screws which adjust how much air to each side
of the manifold. Closing the main one shuts the air off to the other
2. These are only used during the setting of the mixture screw when
using an exhaust analyzer, at all other times they should be left
alone. The problem is that they are so tempting, most mechanics think
that tweaking them will fix things and in most cases they wind up
leaving them open. This reduces the ability of the idle speed motor to
control the air going into the motor so it cannot accuratly keep the
idle set. Usually when I find the screws (at least the main one) open
I find other things that are not right. On most cars I have seen the
other 2 (balancing screws) are open a little. Don't rush out to your
garage and close them. It is only important for the one with the slot
(the lowest one on the engine) to be closed. You should be able to
turn them with your fingers, not a wrench although there are flats for
a wrench. BTW this same advice applys to the old carburaters where
they had idle screws to adjust the idle mixture. They were always
brass and had the same warning.
David Teitelbaum
vin 10757


--- In dmcnews@xxxxxxxxxxxxxxx, Peter Lucas <lucas@xxxx> wrote:
> 
> On Friday, March 14, 2003, at 10:16 AM, David Teitelbaum wrote:
> >
> > Check the 3 brass screws on the intake, they should be LIGHTLTY closed
> > (clockwise)
> 
> I've been wondering this for years:
> When referring to these three screws, everybody always emphasizes that 
> they need to be closed "LIGHTLY". Why, exactly, can't I close them 
> "moderately" or even "tightly"? Is there actually a reason, or is this 
> a DeLorean urban myth?
> 
> --Pete Lucas
> VIN #06703