1slowCamaro

"If your ltrims are positive at WOT, then you need to richin up your Ltrims. and if yoru ltrims are at 20 at WOT, then you need to richin it up ALOT!"
"Richin up your ltrims about 10% and then see what changes you get from there and make changes as you go,, put your 02's at 0 until you get 0 lrims at wot"

How do I go about doing this in Edit? Thanks!

Zshark

I have a similar problem, my Ltrms are often that high too. NoGo said this to me:
https://ls1tech.com/ubb/ultimatebb.p...;f=23;t=002566

NoGo

iTrader: (2)

The rule of thumb when adjusting your LTerms via the MAF translator table is to multiply the table by the % amount your LTerms are reported.

For Example: If your LTerms hang out at +6 all the time, you multiply your MAF table by 106. If your LTerms hang out at -6 all the time you multiply your MAF table by 94.

For small adjustments to the a/f ratio, I usually advise using the MAF transfer function tables to get the LTerms within 10%.

For large changes made to the fueling I make changes to the injector delivery tables, because I fear that large changes to the measured incoming air flow may have adverse affects on other reference tables.
For example: Increasing your MAF transfer function table by 120 (20%) MAY cause you to run into problems with your timing being referenced too low because your g/cyl on the timing table will be off. You will then have to tune your timing table to get the most out of your car.....

And for anybody making large changes to the a/f ratio it is always best to put the thing on a wideband and find out how your WOT a/f ratio faired in the tuning.

Good Luck
<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

1slowCamaro

So NoGo what can I do since my LTFTs hang around 20? You said I probably shouldnt adjust the MAF translator table to compensate for 20% but would 10% do any harm to any other tables? If not and I did that, what could I do to fix the other 10%? What could I do to the injector delivery tables? Dont even think I've looked at those before.

This sucks because that tells me its running lean when the frickin EFIlive tells me I'm at 11.7:1 everytime I floor the frickin gas. A lot of good that thing is.

NoGo

iTrader: (2)

You have to remember, that your car has two differnet a/f ratio's that it shoots for during driving.

During normal around town driving the target a/f of your car is 14.8 to maintain emmissions and economy

At WOT the target a/f ratio of your car is around 12.8

When your car goes WOT extra fuel is added as per the Power Enrichment tables. These tables increase the amount of fuel as a percentage so as to maintain around 12.8 a/f ratio. This fuel is added as an open loop consideration. The normal percent increase in fuel at WOT is 24% at peak HP.
Positive LTerms at part-throttle are added to the PE when the car goes WOT. This could very well cause your car to go pig rich, because you are no longer just adding 24% fuel at WOT, but 24% + LTerms.
Negative LTerms at part-throttle are dismissed for WOT addition.

I would go with the above advice and bump up your MAF table by 10%, then see where you are at.
It is also important to give your car sometime to adjust itself.

WicketMike

iTrader: (13)

click on the Fuel tab, then click on MAF so you goto the MAF table, then put in 110 and click multiply in the bottom right hand corner, then click apply.
start there and see what changes you get

1slowCamaro

When i was looking over my log files last night I noticed that my LTFTs are actually up to 25 but before I turned the COT off they ranged from -2 to 8. That tells me I might want to turn it back on and adjust from there.

There are two separate LTFT readings. I'm guessing one comes from each O2 sensor. Theres one thats nearly always at 25 and one that at like 15. If I turn the COT back on I'll probably also experiment with richening up a small percentage. Maybe multiply by 104 to start and see what that does. The more positive the Ltrims the more lean you run right? What do you think about turning the COT back on? Would you consider it a bandaid fix? Thanks for all the help youve been giving me NoGo.

Justin

<small>[ September 27, 2002, 10:08 AM: Message edited by: 1slowCamaro ]</small>

NoGo

iTrader: (2)

I am pretty sure that turning off your COT protection isn't going to affect your part-throttle LTerms, because COT is something that primarily comes into play at WOT above 5000 rpms. I am by no means the LS1 PCM authority though, so it may be worth a try.
More than likely what happened is that your car had adjusted itself down to around -2 to 8 LTerms on its own, and when you wrote to the PCM again you deleted all of the LTerms adjustment data.
I always read my car first, make changes to that read file and then write to the car. This way if there is any imbedded information that the car has been working on, then it goes back in the PCM.... at least that is what I hope for. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

25% LTerms is a lot, and will eventually set an SES for an excessivly lean condition. Your car will not correct for more than 25% LTerms, so basically, your car is pegged out trying to correct for the excessivly lean condition.
Excessive lean conditions don't happen very often from just a setup. The most common causes of pegged LTerms are
1) Ported MAF reporting too little air flow
2) MAF boofed for some other reason (you touched the resistors etc...)
3) Exhaust O2 sensor not reporting correctly. Bad O2 sensor
4) Vacuume leak at intake.
5) Exhaust Leak exposing O2 to excessive air
6) Faulty Injector
7) Inadequate Fuel Pressure
8) IAT all fooked up
9) Bad programming

You are correct that LTerm B1 represents O2 B1 (drivers side) and LTerm B2 represents O2 B2 (passenger side).
Being your LTerm banks differ so much, I am going to lean towards an exhaust leak or a fuel problem on that side that is reading LTerm 25.
Are you getting any SES codes?

If you would like, send me your latest PCM file, and I will have a look at it to make sure that there isn't something in your programming messing you up. There is nothing worse than a bad program, because the problems are so ellusive.

Good Luck
<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

1slowCamaro

Kevin I will send you my file when i get home around 3pm. I wish I could send you some log files but I think I remember you saying you dont have EFIlive. I have autotap but they didnt give me a registration key so I cant use it. I've been too lazy to call them.
I could see how I might have an exhaust leak because my car always smells when I get on the gas. People tell me this is from not having cats but I'm not to sure about that. I have no cats on my mustang and that thing doesnt smell. If the header isnt tightened down good enough could air get in there? I wouldnt think so, I would think exhaust gas would just leak out but again I dont know. On the passenger side I had a header bolt that I could not get in. It would go half way and stop over and over so I just left it. That is also the bank where it reads 25 Ltrims. I have SES codes but I dont know how to look at what they are. I never really tried to figure that out but I probably should.

1slowCamaro

Just out of curiosity could running straight 110 Unleaded race gas have anything to do with these problems? I doubt it does but I started doing that around the time I turned off the COT. Just a thought.

NoGo

iTrader: (2)

I usually mix Unleaded 110.

I have never A-tapped with race gas; I have nothing to hold the laptop in place on the corners <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> So, I don't know how it affects the car. I suspect, though, that it will make little if any changes to the LTerms.

If anybody would care to chime in with some information on this, it would be helpful....

<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

<small>[ September 27, 2002, 03:07 PM: Message edited by: NoGo ]</small>

TooManyIDs

Interesting comments:

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">NoGo:
For large changes made to the fueling I make changes to the injector delivery tables, because I fear that large changes to the measured incoming air flow may have adverse affects on other reference tables.
For example: Increasing your MAF transfer function table by 120 (20%) MAY cause you to run into problems with your timing being referenced too low because your g/cyl on the timing table will be off. You will then have to tune your timing table to get the most out of your car....
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">1slowCamaro:
I could see how I might have an exhaust leak because my car always smells when I get on the gas. People tell me this is from not having cats but I'm not to sure about that....</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I had my MAF table scaled by about 122%. LTFT's were zero to slightly negative. Even with my PE table scaled down, and a 12.6:1 ratio on the wideband, I was smelling fuel at WOT, while driving and on the dyno. Also, saw what appeared to be COT, when above 6K RPM, AF ratio took a dive.

Moral: NoGo touched on the relationship to other tables when scaling the MAF table. Even though I had made an extra 18rwhp, I've gone back to stock programming until I understand more. The fuel smell is gone, too.

SIKLS1

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 1slowCamaro:
<strong>
This sucks because that tells me its running lean when the frickin EFIlive tells me I'm at 11.7:1 everytime I floor the frickin gas. A lot of good that thing is.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Mate the AFR you are looking at in EFILiveV5 is the Commanded Air Fuel Ratio the PCM is trying to achieve.
I would also check that your COT need to be high if you are seeing this in EFILiveV5, but would check with a wideband 02 sensor, here is a site that sell them, Wideband 02 sensor
Excellent unit are i got one, and have build it myself, and check it at a tuner shop WB02 and it is like 0.1 out, not bad for this kit.
Can purchase it build if you don't have the skill at soldering, it is not and easy project to build and must say not the one to build it if is you first or don't have experience with such a complex project.

<small>[ October 01, 2002, 04:13 PM: Message edited by: SIKLS1 ]</small>