Re: Strategy difference auto / man

[Garfield Willis <garwillis@msn.com>]

On Wed, 23 Aug 2000 12:39:50 -0400, "Bruce Plecan" <nacelp@bright.net>
wrote:

>On emisions, without it a sudden snap of the gas in neutral, and as the rpm
>fall the engine can stall due too excessive richenss, and to get the AE to
>TPS / MAP would be really critical without it.  Also, for coasting, it can
>hold the *suggested* rpm a little high, so that during DFCO the motor goes
>really lean, and they can balance emissions out during overrun manuevers.
>  Then for drivability, it cracks oen realy quick and then as you assume a
>cruse throtle setting it runs back in some.  Just tends to give things a
>responsive edge, as far as what the driver *feels*.
>  Now all of this changes somewhat from cal to cal.

Excellent, thanks; just what I needed.

>  For what you have planned, I think just setting the commanded idle rpm
>low, and the setting the idle speed screw to where you want it will be fine.

OK, that's a plan. Be interesting to see what Andy comes up with as
far as IAC motor compatibility between GM & Fuji. Hope springs
infernal.

>Course be nicest to have a hac to see all of what there is for what you want
>to do, and render possibly more of it's functions off.

Sure would. I must tell ya that one big boogie-man bugaboo about using
OEM controllers in XA is the fact that "we don't know what the code
might do". Having a full hac where everything's visible would go a
long way to dispelling these fears. It's quite possible tho, that
looking at ANY representative GM hac would help give warmNfuzzies.

For example, it's known that on the Soob/Fuji's, the only place where
it can go to fuel-cut (shuts half the injectors off; talk about going
limp!) is if at idle, the ecu thinks it's lost control of the
IAC/idle-rpm (can happen from a induction leak, for example), but this
mode cannot be entered at large throttle settings, so initial fears of
losing half the jugs inflight from such a fuel-cut mode were
eventually dispelled. I'd bet seeing any example of representative GM
code might be sufficient to give the sense of "knowing the code" to a
satisfactory level. Duzn't rule out the possibility of some odd warts
in particular part nos, of course.

Gar


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