Bob Tom wrote:
> At 10:53 PM 4/3/00 -0500, you wrote:
> >A lot of it has to do with how you drive it to, if the computer learns
> >your driving style to be fast, it will put out more power. If you "putt putt"
> >around town, then go to the track, the computer is less likely to put the
> power
> >to the ground.
>
> I'm submitting this information to generate a discussion. Dakota/Ram
> <huge snip>
> SUMMARY.
> The only thing that the computer stores are long term averages of the value
> that the O2
> sensor has sent to the PCM as it attempts to maintain a stoich mixture
> under idle, WOT, etc.
>
> When the computer is cleared, these averages are reset to 128, representing
> no change.
>
> The computer does not learn hard acceleration habits because the computer
> enters the Power
> enrichment mode which turns off the Learn mode during hard acceleration.
>
> To those DMLers who are interested, let her rip on the presented info. and
> conclusions.
I've read this exact text before but can't remember the source. Could it be that
magazine on nothing but Fuel Injection put out by Peterson (I think) several
months ago? Just a guess. If so - that info was largely GM related - not sure
about the 128 stored in the block learn mode (sounds GMish to me). Anyway, we
indeed do have what scan tools call a "Long Term Fuel Trim" that I assume gets
stored somewhere in the computer. I believe that a learned computer will provide
more power than an unlearned version but the learning is mostly done while easy
drivin I agree. Since they are relative to rpm and map - perhaps hard driving
helps learn the higher quadrant quicker and this is how the myth started. I do
understand that PE mode might disable the learning but believe me - the computer
doesn't stay in PE for long. For example if you stab the throttle and keep it
nailed to the floor. Maybe for the first few seconds you are in PE but then
closed loop takes over and you'll be learning those higher quadrant (high rpm -
high load) cells rapidly due to the constant TPS. PE is invoked by things like
rapid delta-TPS and rapid delta-MAP. These are "driveability" type issues that
most cant quite comprehend. I like the part about the runnin in open-loop while
in closed-loop. This is exactly what I was referring to in some previous posts -
I call them "enrichment modes" so as not to confuse the masses 8-) I've got some
new texts coming soon that deal with the Chrysler computer at a lower level so I'm
hoping to be able to provide some better insight soon. The texts are Chrysler
Powertrain Diagnostics type stuff - maybe they will help. I've already considered
quitting my regular job to go to work for Chrysler just to get the goods but am
not that anxious to take a 40k pay cut - maybe just volunteer on weekends or
something (wife would just love that).
Cool conversations for sure - Jon must be lovin it - right Jon? I'm waiting for
Kuk to join in too, and Bill maybe 8-)
Latr,
Shane
ps - Could this be the same Kuk from many moons ago that inspired me to do my own
TB mods? My buddy says I "hawged that baby out with a dremel tool" 8-))
-- '96 IndyRam-HisIndy-MPI/TB/Pulleys/Coil/Wires/CompTAs '96 IndyRam-HerIndy-numbered(#142)"Track Truck" '74 Triple-Black Dodge Challenger Rallye 360 home-brew EFI R&D vehicle '68 Black Corvette Convertible 427 (For Sale)
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:50:36 EDT