RE: Franco gear

[Aleksander Mierzwa <alex@matrix.com.pl>]

But there are systems that do not use any camshaft related sensors at
all. For example, Renix system used on some Renaults, Jeeps and Volvos
has only one sensor at the flywheel that is used for both engine rpm
readout and ignition timing. How do these systems distinguish firing
stroke from induction stroke?
Just curious.

Aleksander Mierzwa
Warsaw, Poland
mailto:alex@matrix.com.pl
87 Audi 5000CS turbo (mine)
88 Renault Medallion wagon (mom's)
91 mountain bike (just in case both cars broke at the same time :-)

> -----Original Message-----
> From:	quk@isham-research.demon.co.uk
> [SMTP:quk@isham-research.demon.co.uk]
> Sent:	Friday, November 14, 1997 4:01 PM
> To:	quattro@coimbra.ans.net
> Subject:	Franco gear
> 
> Remember - I'm obsessed with turbos and their ECUs.
>  
> However - it seems that the distributor Hall effect sensor is not used
> for any 
> timing purpose at all.  The flywheel sensors offer much greater
> precision for 
> triggering timing - but the flywheel revolves _TWICE_ per firing cycle
> against 
> the camshaft and distributor's one rotation.
>  
> I think in some applications the Hall sensor serves only to
> differentiate a #1 
> TDC _firing_stroke_ from a #1 TDC _induction_stroke_.  As far as the
> flywheel-
> based sensors are concerned, these events are indistinguishable - a
> 'phase' 
> signal is required to determine which of the two flywheel pulses
> within a 
> complete cycle is actually the firing stroke.  Once this is done, the
> ECU can 
> disregard the Hall sensor completely.
> 
> -- 
>  Phil Payne
>  Committee Member, UK Audi [ur-]quattro Owners Club