Re: [DML] 3 Brass Screws Infront Of Engine

[Martin Gutkowski - DMC Ltd <martin@xxxxxxxxxxxxxx>]

Errrm.... almost entirely inaccurate I'm afraid...

The idlespeed system is a closed-loop system and is designed to keep the 
idle constant regardless of temperature or load, so when the fans kick 
on, you may well see a sudden drop in RPM followed by it picking back up 
again to 850 plus-or-minus 25 (ignore the rev counter, it's not that 
accurate). Adjusting the brass screws may allow too much air in if you 
keep going to beyond the point where the idlespeed motor can compensate, 
although taking it up to this threshold can be beneficial. You won't 
create mixture problems because the air passing through the "screws" is 
metered, unless you back them off so far that you create a vacuum leak.

A quirk of the system is that a rich running engine sends the idlespeed 
into oscillation - a condition experienced on a cold engine with lambda 
(original, in other words)

Martin

stainlessilusion wrote:

>As a side note:
>The idle speed motor regulates the amount of air going into the
>engine, thats why when your cooling fans kick on- your engine revs
>higher to compensate for the increased power draw (Increasing
>air=Increased RPMS=More power from alternator)-the idle motor adjusts
>allowing additional air to increase the RPMS. Adjusting the screws
>with the idle motor will possibly allow too much air, which will
>eventually lead to mixture problems depending on how much extra air it
>is getting.
>  
>







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