RE: Ignition Timing...

[Bill Samaras DTN 223-7322 31-Aug-1993 1324 <samaras@wrksys.enet.dec.com>]

The ignition timing is controlled by the engine management computer. The
distributor has no adjustments.  There is no advance mechanism built into the
distributor. The computer listens to engine knock through a knock sensor, and
gets temperature info through temp sensors. With this (and other) info, the
computer looks up the proper advance/retard setting in a timing map stored in
its memory. The computer "tells" the ignition coil when to fire each plug and
can advance or retard between each firing of each plug. In addition, idle speed
regulation is accomplished somewhat by adjusting timing at idle.

In general, you can't do a better job than this.  With this setup, using higher
octane gas will let the computer give you extra advance thus giving you more
power. 

In all probability, you will never need to service this system; it just works
well all the time.

good luck with your car,
...bill


>Since I haven't bitten the bullet and bought the Bentley book, I pose some 
>simple questions...
>
>What must be disconnected, jumpered, or plugged to set the ignition timing on
>the 2.3L?  (Mine is a 1988 90Q)
>
>Any special tools?
>
>What should it be set to for above mentioned car?
>
>Will running slightly advanced with high grade fuel give better performance
>on these engines? (ie. +2deg and 89/92 octane)
>
>Thanks in "advance" (oooohhh, yourself)
>Chris