Need help Tuning (lazy O2 sensors)
09-30-2015, 08:14 PM
#1
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Need help Tuning (lazy O2 sensors) Okay so I buddy and I was just trying to tune my 98 Z28 M6. I just bought. It has BBK intake, Long tubes , Z06 cam, No cats and now a magna flow muffler.. This is all I was told about the car, from pervious owner. It was suppose to have LS6 heads but it does not( has 806 heads). Anyway I was driving it around and it does not idle correctly Like at 1000 rpm so I wanted to get it down to 750... So decided to spend the money buy the credits to tune the car.
We are getting rich idle at 800 to 1400 rpm, have lazy 02 readings and don't know where to go from here. Any help will be appreciated .
Thank you in advance
We are getting rich idle at 800 to 1400 rpm, have lazy 02 readings and don't know where to go from here. Any help will be appreciated .
Thank you in advance
10-02-2015, 08:32 PM
#3
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After you get it in a known-un-munged state, I'd start
with closed loop disabled and get it to idle clean with
open loop fueling and open loop idle (no closed loop
RPM control). Then, enable closed loop idle control and
deal with any stability issues there without allowing the
PCM to false-trim you fat. Although you could play with
idle stability at a somewhat rich position just to ensure
you have some margin there. Only at the end do you
want closed loop fueling (which the long tubes and the
froze-out O2s will bugger, at idle) in the mix. That is
almost certain to destabilize idle but at least you'll know
why, if the rest is clean.
Look at improving heat retention in the collectors and
lower part of the primary tubes, up to maybe 6" past
the O2 sensors. That might help the O2 sleepy situation,
somewhat.
with closed loop disabled and get it to idle clean with
open loop fueling and open loop idle (no closed loop
RPM control). Then, enable closed loop idle control and
deal with any stability issues there without allowing the
PCM to false-trim you fat. Although you could play with
idle stability at a somewhat rich position just to ensure
you have some margin there. Only at the end do you
want closed loop fueling (which the long tubes and the
froze-out O2s will bugger, at idle) in the mix. That is
almost certain to destabilize idle but at least you'll know
why, if the rest is clean.
Look at improving heat retention in the collectors and
lower part of the primary tubes, up to maybe 6" past
the O2 sensors. That might help the O2 sleepy situation,
somewhat.
10-03-2015, 12:21 AM
#4
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It does start and drive ( drive it daily). Never had an issue with that, but I figured it could use a tune, with the add on;s and the ls6 cam, which will be replaced in the future(soon) ( Looking for a cam now) .. Just trying to get it right... just need some help....