Totally Stock - Way Too Much Knock - UPDATE page 3
#41
Senior Member
Certified Car Nut
Thread Starter
Join Date: Oct 2002
Posts: 11,308
Likes: 0
Received 0 Likes
on
0 Posts
![bonnie94ssei is on a distinguished road](https://www.gmforum.com/images/reputation/reputation_pos.gif)
![Default](https://www.gmforum.com/images/icons/icon1.gif)
So though +6.2 indicates a lean condition, overall it'* not horribly lean (otherwise my KR would be much higher), but the fact that the PCM was able to adjust the fuel is all that matters. It'* just a known fact that the CLOSER to 0 you are, the better (since at WOT you'll likely never have a 0.0 for LTFT).
So it is possible to have 0 KR and an LTFT of +6.2?
Am I wrong in anything I stated?
So it is possible to have 0 KR and an LTFT of +6.2?
Am I wrong in anything I stated?
#42
Senior Member
Certified Car Nut
Join Date: Oct 2003
Posts: 19,756
Likes: 0
Received 0 Likes
on
0 Posts
![1993 SLE is on a distinguished road](https://www.gmforum.com/images/reputation/reputation_pos.gif)
![Default](https://www.gmforum.com/images/icons/icon1.gif)
i just did a few WOT pulls from a Stop tonight, just for fun
my LTFT'* were +6.2
i had only had KR at the top of the gear 4500RPM'* +
and timing was 14.0 untill i had 1-2* of KR...then i saw 12.0-12.5 timing
my LTFT'* were +6.2
i had only had KR at the top of the gear 4500RPM'* +
and timing was 14.0 untill i had 1-2* of KR...then i saw 12.0-12.5 timing
#43
DINOSAURUS BOOSTUS
![](/images/badges/Gearhead.png)
Expert Gearhead
![Default](https://www.gmforum.com/images/icons/icon1.gif)
I believe Paul is saying that the PCM is seeing the car running lean according to the O2, it sees the average fueling needing 6.2% of the fueling added to it to meet the programmed expected values.
6.2% is not considered goodl. 16.4% is even worse.
On that..never seeing 0, It is possible with proper tuning to get extremely close to 0 and most of the time be at 0.
6.2% is not considered goodl. 16.4% is even worse.
On that..never seeing 0, It is possible with proper tuning to get extremely close to 0 and most of the time be at 0.
#46
Senior Member
Certified Car Nut
Thread Starter
Join Date: Oct 2002
Posts: 11,308
Likes: 0
Received 0 Likes
on
0 Posts
![bonnie94ssei is on a distinguished road](https://www.gmforum.com/images/reputation/reputation_pos.gif)
![Default](https://www.gmforum.com/images/icons/icon1.gif)
Well it'* been a while since I updated this. I figure FWIW I will now, because I really have to figure out my issue(*).
Driving around town at 35-40mph and ~1300 rpms I was getting KR constantly and consistently this weekend. 2.5* or less. I noticed that when I get this "phantom" KR, my LTFT is high also. Once the fuel trim hits 9.3 I start getting KR, and it may hit 2.5* and then trickle down. Once it gets to 0.0, it peeks again at 2.x* and trickles back down to 0.0. Once it starts doing this it keeps doing it. And this weekend just creeping around town at 35-40, my LTFT was consistently above 10.9, sometimes at 14.
So at least part of my issue/cause of KR must be a fuel problem, right? Or could it possibly be incorrect readings from the MAF which is in turn telling the PCM I'm running very lean. What kind of readings should I be getting from a properly working MAF?
I just don't understand how the hell I could be running SO LEAN at 35mph that the PCM is adding 14% fuel. I've checked for vacuum leaks way too many times already and I can't find any.
So does anyone have any advice on what I should be looking for based on my experience this weekend? Any other things I should be checking for on the Aeroforce when this is happening?
Driving around town at 35-40mph and ~1300 rpms I was getting KR constantly and consistently this weekend. 2.5* or less. I noticed that when I get this "phantom" KR, my LTFT is high also. Once the fuel trim hits 9.3 I start getting KR, and it may hit 2.5* and then trickle down. Once it gets to 0.0, it peeks again at 2.x* and trickles back down to 0.0. Once it starts doing this it keeps doing it. And this weekend just creeping around town at 35-40, my LTFT was consistently above 10.9, sometimes at 14.
So at least part of my issue/cause of KR must be a fuel problem, right? Or could it possibly be incorrect readings from the MAF which is in turn telling the PCM I'm running very lean. What kind of readings should I be getting from a properly working MAF?
I just don't understand how the hell I could be running SO LEAN at 35mph that the PCM is adding 14% fuel. I've checked for vacuum leaks way too many times already and I can't find any.
So does anyone have any advice on what I should be looking for based on my experience this weekend? Any other things I should be checking for on the Aeroforce when this is happening?
#47
DINOSAURUS BOOSTUS
![](/images/badges/Gearhead.png)
Expert Gearhead
![Default](https://www.gmforum.com/images/icons/icon1.gif)
Pat was also running in that same range Pete..
I tweaked his injectors as a temp fix. His fuel trims appear to be good now, he'* still got a little KR. Not as bad though.
I tweaked his injectors as a temp fix. His fuel trims appear to be good now, he'* still got a little KR. Not as bad though.
#48
Senior Member
Certified Car Nut
Thread Starter
Join Date: Oct 2002
Posts: 11,308
Likes: 0
Received 0 Likes
on
0 Posts
![bonnie94ssei is on a distinguished road](https://www.gmforum.com/images/reputation/reputation_pos.gif)
![Default](https://www.gmforum.com/images/icons/icon1.gif)
So should I be checking injector PW on the gauge? What are considered proper readings for this? Should I disconnect the battery to reset the trims for chits and giggles?
#50
DINOSAURUS BOOSTUS
![](/images/badges/Gearhead.png)
Expert Gearhead
![Default](https://www.gmforum.com/images/icons/icon1.gif)
No need to look at them...
IPW is dependent on what your pcm is telling it to do. Some cars can be lean at 15ipw and others at 20..
We'd need to look at a few parameters..but nothing is like true tuning.
IPW is dependent on what your pcm is telling it to do. Some cars can be lean at 15ipw and others at 20..
We'd need to look at a few parameters..but nothing is like true tuning.