Doc99SShome

J&J, so you have a VIG3200 stall convertor, I have a Vig 3000 stall TC in my '87 IROCZ, but I have not done any Eprom tuning based solely on the TC.

If you are between 5% and 10% for LTFTs, I guess that you could go either way. But if you have been looking around in other post, you would know that I prefer modifing the MAF table IF a good method is used. A blind across the table multiplication is not a good method, especially with an automatic car. I have been involved in too many debates on this point. You will have to investigate the matter yourself. But if you have saved the factory PCM tables in LS1Edit, you can always go back to the stock MAF table if you detect a problem with your car having made a MAF table change.

BTW: You might be running a little rich on top end because the +7 to +9% LTFTs are adding extra fuel in during PE, up and above the PE vs RPM table is doing. You want to tune the LTFTs down to close to 0%,,, the most important LTFT value is the one used for WOT, most likely fuel cell 15, but I'm not sure on this point.

<small>[ February 27, 2003, 08:27 PM: Message edited by: Doc99SShome ]</small>

2K T/A Driver

Doc - You have a wealth of knowledge.. I have been reading your posts all over ls1.com all day long...

Thank you for answering my question.. Firstly, I already have the stock "tune" saved to 3 different disc's.. 1 being in a firesafe.. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

So basically, instead of buying another MAF, I can just simply mod the MAF table to work with this MAF and not expirence the problems.. Correct?

Anyway, I think I speak for all the newbies to LS1Edit when i said, we all greatly appreciate people like you who take their time to answer questions.. Also, honestly, there is nothing like reading a debate between two knowledgeable people on how things should be done.. It's very informative.. I am still searching these sites for your description on how to mod the MAF table..

J&JsTa - I am running so rich, I have expirenced a great loss of gas mileage.. i went from 240 per tank to barely 200...

Doc99SSx

2K, thanks for the comment.

Yes, dont spend any money concerning your MAF sensor, at least not yet. Attempt to re-calibrate your MAF table. Do a search on "frequency" and "smooth" and maybe "curve" in order to find the method that I use. The method is written as a general method. Each case is different. You will let your LTFT values guide you in how much & where (which frequency cells) will be changed in the MAF table.

2K T/A Driver

Doc,

I was told to check for a vacuum leak on Ls1.com, so I thought it couldn't hurt..

so I did this, took carb cleaner sprayed it around the engine...

I found a leak... the EGR tube into the intake.. when I spray there the idle raises if i lightly spray around it.. if i soak it, the idles drop and white smoke comes out the exhaust...

Soo... could this be part of my problem??

Also, i have EGR block off plates on the way, I am planning on removing all of this...

Jeff

Doc99SShome

Yes, you found what should be the root cause of your high LTFTs. Fix the vacuum leak, and take your car out for a 20 minute drive going up and down thru the gears. As you drive, you can look at the LTFT value when you are going a constant speed (staying in the same fuel cell) and watch the LTFT. If the LTFT value does not change anymore, its time to log some more engine data.
The main point here is that you need to give the PCM time to relearn before a take a new log session.

You should see the LTFT values come down some, but I dont think that they will go to the negative side. Report back here about your findings.

<small>[ March 01, 2003, 04:16 PM: Message edited by: Doc99SShome ]</small>

2K T/A Driver

Ok, well.. I did what I could with the EGR (still waiting for blockoff plates)and did a few runs on the way home from class today...

I had been averaging:
21.7 for the LTFT B1
21.5 for the LTFT B2

well with the little EGR tinkering I just did (i'm still throwing a lean code) I am now averaging:
18.03 for the LTFT B1
18.09 for the LTFT B2

Which is better.. I think it will still come down some more when I get the EGR plates and completely block the hole...