Odd stalling issue
09-23-2014 | 04:51 PM
#1
Odd stalling issue Car: 2001 Camaro A4
Mods: Lid, longtubes, cam (232/234 617/598 112+2) SS3600 converter, 3.42 gears.
Car is tuned, idles fine. While coming to a stop car will sometimes stall for no reason. Not a quick closure of the TB like coming from a burnout, slow driving then a stop.
Ideas?
Mods: Lid, longtubes, cam (232/234 617/598 112+2) SS3600 converter, 3.42 gears.
Car is tuned, idles fine. While coming to a stop car will sometimes stall for no reason. Not a quick closure of the TB like coming from a burnout, slow driving then a stop.
Ideas?
Last edited by Mean87SS; 09-23-2014 at 04:59 PM.
09-24-2014 | 06:51 PM
#6
On some model*year factory files I've seen really kooky
throttle cracker maps which have a "divot" near return-
to-idle which could be a destabilizing "event" if you step
in it and the motor is already struggling a bit. With the
big cam I'd expect idle and transition-to-idle to need a
lot of fine fiddling.
In the attached pic, note how many cells of the cracker
give zero help as you approach idle (left side, stock '02
F-body tune file) and how the airflow adder is jerked
around variably by how you approach 0,0. This could be
a "stimulus" the idle RPM is forced to react to, and that
loop is a soggy piece of **** even when you don't challenge
it with a cam and bad tune data elsewhere (jacked VE,
false trimming, etc.).
On the right is where my setup sits, a smooth and sane
"weaning" as you approach 0,0 from any direction. I
get no idle undershoot except in reverse, a little (a
common issue, I have yet to see anyone say why but
many say "me too").
Have a look at this feature, in your tune.
<note: for some reason my nice high resolution .png file
is turned into a low res crappy .jpg by the site; if you
need a better copy let me know where to email it>
throttle cracker maps which have a "divot" near return-
to-idle which could be a destabilizing "event" if you step
in it and the motor is already struggling a bit. With the
big cam I'd expect idle and transition-to-idle to need a
lot of fine fiddling.
In the attached pic, note how many cells of the cracker
give zero help as you approach idle (left side, stock '02
F-body tune file) and how the airflow adder is jerked
around variably by how you approach 0,0. This could be
a "stimulus" the idle RPM is forced to react to, and that
loop is a soggy piece of **** even when you don't challenge
it with a cam and bad tune data elsewhere (jacked VE,
false trimming, etc.).
On the right is where my setup sits, a smooth and sane
"weaning" as you approach 0,0 from any direction. I
get no idle undershoot except in reverse, a little (a
common issue, I have yet to see anyone say why but
many say "me too").
Have a look at this feature, in your tune.
<note: for some reason my nice high resolution .png file
is turned into a low res crappy .jpg by the site; if you
need a better copy let me know where to email it>
