Ign Advance on MR-2

Diehl, Jeffrey jdiehl at sandia.gov
Sun Aug 12 06:46:56 GMT 2001


I'm about to show my ignorance, but ignorance is only temporary...  

What are you refering to when you refer to the Ne and Ge signals?

I'm assuming you meant Stop notification below...?  But what is a MIL
indication?

Sorry to hear about your TPS connector... <grin> 

Thanx for your input,
Mike Diehl.


-----Original Message-----
From: lance
To: diy_efi at diy-efi.org
Sent: 8/11/2001 11:54 AM
Subject: RE: Ign Advance on MR-2

The 4AG engines use a trap door MAF and throttle position sensor for
spark
timing.  The distributor generates Ne and Ge signals.  You are correct
the
advance is entirely under the ECU's control, and there is no crank
position
sensor per se.  Interestingly, the throttle position sensor can be
completely nonfunctional and the engine still runs without any SOTP
notification or MIL indicating that something is wrong.  If you forget
to
reconnect it, the connector will get chewed up by the left drive axle.
Ask
me how I know.

Lance

-----Original Message-----
From: owner-diy_efi at diy-efi.org [mailto:owner-diy_efi at diy-efi.org]On
Behalf Of Les Newell
Sent: Saturday, August 11, 2001 02:46
To: diy_efi at diy-efi.org
Subject: Re: Ign Advance on MR-2


Hi Mike,
The ECU generates the advance/retard. The wheel with four teeth is to
tell
the ECU when a piston is at TDC and the wheel with one tooth is to tell
the
ECU when piston 1 is at TDC. From this information the ECU always knows
the
crank position. There is probably a vacuum sensor attached to the
manifold
somewhere. From this information and possibly data from other sensors
the
ECU can work out the optimum timing.

Les


> Hi all.
>
> I'm still learning, so be gentle... <grin>
>
> I've got an '87 MR-2 and I'm trying to figure out how it effects
timing
> advancement.  It has 2 wheels in the distributor, one with 4 teeth,
the
> other with 1.  The single-toothed wheel is probably used to run the
tach
and
> is slightly offset from the cooresponding tooth on the 4-tooth wheel.
>
> Now the teeth on the 4-tooth wheel pass by what looks like a magnetic
pickup
> and I presume that this gives the ECM the baseline timing.  However,
it
also
> passes by what looks like a small magnet which is attached to the
pickup.
>
> There are no vacuum lines, so it is not doing vacuum advance.  The
only
> moving part is the shaft on which the two wheels move.
>
> So, my question is: How does this mechanism manage to advance the
spark?
>
> Thanx for any input.
> Mike Diehl.
>
>
------------------------------------------------------------------------
--
--
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
quotes)
> in the body of a message (not the subject) to
majordomo at lists.diy-efi.org
>

------------------------------------------------------------------------
----
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
quotes)
in the body of a message (not the subject) to
majordomo at lists.diy-efi.org

------------------------------------------------------------------------
----
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
quotes)
in the body of a message (not the subject) to
majordomo at lists.diy-efi.org


----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org




More information about the Diy_efi mailing list