Quasi vs. Async vs. Sync?

[rr]

I think each of our last lines sums it up. Every ecm is different
in one way or another. The '747 & '749 methods of handling
the sync to (q)async pulses are different, very different. As is
the terminology.

Another good example of this is where the '747 (and others),
closed loop correction term (CLT), is added or subtracted
from the BPW by summing.

The '749 (and others), the CLT is added or subtracted from
the BPW as a multiplier. A distinct difference.

BobR.

Dig wrote:

> Might be nit-picky, but isn't it the other way around?
>
> IE,  Quasi-Async is when the ECM delivers every-other
> ref pulse due to the minimum pulse width being too
> small; Async is "pump shot" delivery (AE) that happens
> on an as-necessary basis (but within the confines of
> the minor loop)?
>
> This is speaking from a '749 frame of reference...
>
> Later,
>
> Dig
> turbodig at yahoo.com
>
> ------------------------------
>
> Date: Thu, 15 Mar 2001 15:01:57 -500
> From: rrauscher at nni.com
> Subject: Re: May have been wrong all along
>
> Sync is when the injector(s) fire coinciding with a
> distributor
> reference pulse. Async is when the injector(s) fire at
> an 80Hz
> rate. This coincides with the ECM minor fuel loop
> code.
>
> Sync is used 99% of the time. Async is used when the
> desired
> sync pulse is too short to be accurately metered. The
> pulse
> widths for min's, max's, switching between the two are
> all in
> the code (or data tbls).
>
> Then there is the quasi-async pulsing. This is when
> both sync
> and async are taking place together. Such as pump
> shot.
>
> This is how the '747 & '8746 handle it. Others may
> vary.
>
> BobR.
>

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