Re: Why would you have to MOD your CIS ?

[thyrsted2@olsy.dk (Kenn Thyrsted)]

>knock LED ?
Interesting !
-How do i tap into the knock signal *without* disturbing it ?

>At this point, the system is running open-loop and
>significant extra enrichment is provided by the ECU's management of the
>fuel frequency valve.

My JY uses a WGFV to control enrichment via the control-pressure regulator;
and doesn't apply pressure to the upper WG chamber.
-Will this type of CIS be easier to tweak, as ctrl-press will influence on
air mass sensor characteristics ?


Kenn Thyrsted
'87 200(t)Qavant (On Jack Stands)

----- Original Message -----
From: Orin Eman <orin@WOLFENET.com>
To: <quk@isham-research.freeserve.co.uk>
Cc: <thyrsted2@olsy.dk>; <isham-research.freeserve.co.uk@WOLFENET.com>;
<quattro@audifans.com>
Sent: 20. september 1999 02:26
Subject: Re: Why would you have to MOD your CIS ?


>
> > In message <006601bf02c6$c7666560$01181ba1@olsy.dk> thyrsted2@olsy.dk
(Kenn Thyrsted) writes:
>
> > > Seemes to me that you don't have to mod the CIS for running higher
boost..
>
> > > If that's true, - then why do you have to mod the CIS if you're
increasing
> > > volume, eg by using a 2.5l crank etc..
>
> > Because it seems (certainly from my experiments) that the mechanical air
> > mass sensor used in Hitachi-controlled I5 engines maxes out at 4500rpm
> > and full boost.  At this point, the system is running open-loop and
>
> ...and the knock LED says that the MC tends to start knocking
> around 4800 RPM when above stock boost.  The knock sensor catches it
> and retards the timing, but perhaps more fuel is in order rather than
> lots (and I mean LOTS) of timing retard.
>
> Phil, does your type 44 have the MAC14?
>
> Orin.