Turbo Nipple

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <3.0.3.32.19980723094018.0092ebc0@frii.com> Brooks Ellis writes:

>> Idle adjustment screw.

>> On most engines, you need a tachometer and a milliamp meter to adjust
>> it.  A CO meter helps - a Colortune plug will do at a pinch (and is
>> always preferable to a Gunson CO meter).
>
> What do you need the milliamp meter for? And why a CO meter? I understand
> that CO = low oxygen, but why wouldn't the engine compensate for that, and
> put in less fuel, or open the throttle a little?

Well, 'most engines' to me still means CIS-E.  In theory, CO is set
at the metering head - in practice, the idle adjustment affects it
and vice versa.  The classic VDO ISV should, at idle, have 430 mA
passing through it at 800 rpm and (varying slightly) around 1.25% CO.

Touch one, and the others change.  Of course, on fully catted engines,
you have the fuel frequency valve to worry about as well/instead.

--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
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