ATAP Reading Newbie...Please come inside ????
Thread Starter
TECH Fanatic
Joined: Nov 2001
Posts: 1,695
Likes: 9
From: Raleigh, NC
ATAP Reading Newbie...Please come inside ???? Hey Guys, Downloaded the LTFT/ o2 analysis guide and am trying to adapt it to my readings. Pertinent infor I have is Ignition Timing advance, KR, B1S1, and B2S1 readings. The guide says that the WOT 02 average is calculated from B1S1 and B2S1, but how. Just a normal avg ((B1S1+B2S1)/2)?? How do I convert this to A/F, is there an equation? Unfortunately the Wideban was broken on the Dyno.
Here are my readings.
KR 0 across the board (Good)
B1S1 .92V - .95V across the board (Rich?????)
B1S2 .44-.45 across the board (??????)
Ignition timing is 28-30 in the low RPM range but then falls off to an AVG of 25 from 3600 RPM and up.
Please help me figure this out. To me it looks like I am Rich (. 93-.95 ) from 3500 up and giving up some timing 3500 and up (shouldnt it be upper 20s to 30 all the way across the board).
Please advise
How accurate are these readings?????
TIA,
-Nick
Here are my readings.
KR 0 across the board (Good)
B1S1 .92V - .95V across the board (Rich?????)
B1S2 .44-.45 across the board (??????)
Ignition timing is 28-30 in the low RPM range but then falls off to an AVG of 25 from 3600 RPM and up.
Please help me figure this out. To me it looks like I am Rich (. 93-.95 ) from 3500 up and giving up some timing 3500 and up (shouldnt it be upper 20s to 30 all the way across the board).
Please advise
How accurate are these readings?????
TIA,
-Nick
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Re: ATAP Reading Newbie...Please come inside ???? "B1S2 .44-.45 across the board (??????)"
That sensor isn't working at all and will need to be replaced. Those readings are by default. You'd get the same thing if you unplugged the sensor.
The other one appears to be running a little rich. Make sure the PCM has had plenty of time to make adjustments since the last time it was reset or since the last time you've made a mod (a hundred miles and several WOT blasts should be enough) and if those readings are still that high you may benefit from leaning the mixture out a bit. Your timing advance will probably come up some when the mixture is leaned back out and the faulty O2 sensor is replaced.
You said timing averaged 25 but what is it at 6000 RPM?
<small>[ December 02, 2002, 07:16 PM: Message edited by: Colonel ]</small>
That sensor isn't working at all and will need to be replaced. Those readings are by default. You'd get the same thing if you unplugged the sensor.
The other one appears to be running a little rich. Make sure the PCM has had plenty of time to make adjustments since the last time it was reset or since the last time you've made a mod (a hundred miles and several WOT blasts should be enough) and if those readings are still that high you may benefit from leaning the mixture out a bit. Your timing advance will probably come up some when the mixture is leaned back out and the faulty O2 sensor is replaced.
You said timing averaged 25 but what is it at 6000 RPM?
<small>[ December 02, 2002, 07:16 PM: Message edited by: Colonel ]</small>
Re: ATAP Reading Newbie...Please come inside ???? Nick,
B1S2 is your post cat sensor and now it is probably a O2 sim so this should be ignored. The O2 sensors you need to check are b1s1 and b2s1
Also, O2 as WOT are not accurate and you really need to get a WideBand setup to see you AFR. I have seen post where .940mv was around 12.8 AFR (see posts by NoGo - Post )
- Tom
B1S2 is your post cat sensor and now it is probably a O2 sim so this should be ignored. The O2 sensors you need to check are b1s1 and b2s1
Also, O2 as WOT are not accurate and you really need to get a WideBand setup to see you AFR. I have seen post where .940mv was around 12.8 AFR (see posts by NoGo - Post )
- Tom
Thread Starter
TECH Fanatic
Joined: Nov 2001
Posts: 1,695
Likes: 9
From: Raleigh, NC
Re: ATAP Reading Newbie...Please come inside ???? Hey Guys,
Thanks for the input.
Colonel- The timing is 25 at 6000 RPM. It averages 25 (24.5-26) all the way from 3500 to 6K. This was my main concern with loss of power from this tune. The car was LS1 Edited (Turned off Rear o2s) and ATAPed on the dyno but wideband was broken <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> . The car was leaned out 8% total after the LT install. And we did see some upper RPM pinging, so we put a little back in up top.
Tom- Thanks for that post. I do need to get it back on the dyno with Wideband sometime, but I am thinking I have a pretty good conservative A/F. To be honest The timing was what concerned me the most.
Do you guys think my Timing table is screwed up?
TIA,
-Nick
<small>[ December 04, 2002, 01:48 PM: Message edited by: niphilli ]</small>
Thanks for the input.
Colonel- The timing is 25 at 6000 RPM. It averages 25 (24.5-26) all the way from 3500 to 6K. This was my main concern with loss of power from this tune. The car was LS1 Edited (Turned off Rear o2s) and ATAPed on the dyno but wideband was broken <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> . The car was leaned out 8% total after the LT install. And we did see some upper RPM pinging, so we put a little back in up top.
Tom- Thanks for that post. I do need to get it back on the dyno with Wideband sometime, but I am thinking I have a pretty good conservative A/F. To be honest The timing was what concerned me the most.
Do you guys think my Timing table is screwed up?
TIA,
-Nick
<small>[ December 04, 2002, 01:48 PM: Message edited by: niphilli ]</small>
Thread Starter
TECH Fanatic
Joined: Nov 2001
Posts: 1,695
Likes: 9
From: Raleigh, NC
Re: ATAP Reading Newbie...Please come inside ???? Hey Guys,
Think I got my explination. It looks like GM pulled timing out in the mid range because that is where these cars tend to detonate. Basically my timing holds at 30 untill 3500 where it drops to 25 and holds pretty constant there until 6K. I guess this is a good safe tune. Will post results if I ever get the chance to look at wideband and compare that to my o2 readings.
-Nick
Think I got my explination. It looks like GM pulled timing out in the mid range because that is where these cars tend to detonate. Basically my timing holds at 30 untill 3500 where it drops to 25 and holds pretty constant there until 6K. I guess this is a good safe tune. Will post results if I ever get the chance to look at wideband and compare that to my o2 readings.
-Nick
