smokin' joe 00 ss

Well I've reset the PCM 2 times now and I've gone from 10% rich to 20% rich for the base setting on my maft and the WOT is set at 0 and there is no change and each time I put about 70 miles on it. I've checked for air leaks after the maft I just can't seem to bring the LTFT's down and get the 02's were they need to be. Cruzing around the LTFT's are around 10-11%. I wounder if my GMAF is screwing up on me? Any help would would be great .
Thanks, Joe

Reckless

iTrader: (9)

As long as your LTrims are "+", your PCM will add fuel at WOT. If your O2s are on the rich side at WOT, you should try to get on the "-" side for your LTrims. If you're rich at cruise (i.e. "-" LTrims), your PCM will take out a little fuel at WOT.

So work on getting your LTrims to about -5 during part throttle cruise. After that settles, then check your O2s at WOT.

smokin' joe 00 ss

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Reckless:
<strong>As long as your LTrims are "+", your PCM will add fuel at WOT. If your O2s are on the rich side at WOT, you should try to get on the "-" side for your LTrims. If you're rich at cruise (i.e. "-" LTrims), your PCM will take out a little fuel at WOT.

So work on getting your LTrims to about -5 during part throttle cruise. After that settles, then check your O2s at WOT.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Well thats my goal I'll just have to put some more miles on it and see what happens because I've got the maft set as rich as it will go on the base setting, Thanks

blazinredls1

so reckless, ur saying if im to rich on my 02's, i should try and get "-" on my ltrims? I thought it was u wanted postive ltrims? I am heavily rich on my 02's but was seeing negative ltrims at cruise, i tryed and adjusted my ltrims to get them postive, am i wrong?

Brother J

The other school of thought is to adjust your base settings so that you get the best timing advance with the lowest (usually positive LTrims) and then adjust the WOT setting to get your 02's in the zone you are seeking

Reckless

iTrader: (9)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by blazinredls1:
<strong>so reckless, ur saying if im to rich on my 02's, i should try and get "-" on my ltrims? I thought it was u wanted postive ltrims? I am heavily rich on my 02's but was seeing negative ltrims at cruise, i tryed and adjusted my ltrims to get them postive, am i wrong?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Positive LTrims at part throttle cruising means you are LEAN, and the PCM will err on the safe side at WOT and add fuel.

Negative LTrims at part throttle cruising means you are RICH, and the PCM will not add fuel at WOT unless you instruct it to add fuel.

Todd

Slowhawk

iTrader: (12)

Take off the GMAF and see what you get.I've seen MAF ends really lean a car out so you have to set Base to 20% rich to get it back in the ballpark.

smokin' joe 00 ss

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Slowhawk:
<strong>Take off the GMAF and see what you get.I've seen MAF ends really lean a car out so you have to set Base to 20% rich to get it back in the ballpark.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">OK thats my next move, Thanks

Orange Krush

[QUOTE]Originally posted by Slowhawk:
"Take off the GMAF and see what you get.I've seen MAF ends really lean a car out so you have to set Base to 20% rich to get it back in the ballpark."

Don U wouldn't be refering to me now would U ? <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

smokin' joe 00 ss

Well I put the stock maft on and reset the pcm and put about 80 miles on the SS and the Ltrims are still about 25.0% at idle and still rich at WOT .935 <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> but the car runs really strong, it seems like any ajustment I made on the maft didn't make any difference. I wounder if the maft is bad is ther a way to tell if the maft I bought out of the for sale section is any good?

ChrisB

If going from a ported to stock MAF made no difference on your l-trims then something is wrong.

Is the problem only at idle, or at all rpm's/loads. If it's only at idle it sounds like an exhaust leak - if it's at all cells I would check my o2's next.

Chris

smokin' joe 00 ss

I don't here any exhaust leak but I'll get under her and check and I'll put some new egr gasket on too, my ltrims at cruz were around 4.7 to 10 and WOT were .935, Ive got the stage 8 header bolts and locks so I don't think it's leaking around the heads. Oh well it's kind of fun researching the problem and working on the SS too I really love this stuff <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />

JimMueller

iTrader: (9)

I'd completely ignore your O2's at WOT. I followed recommendations by some internet folks and tried getting my O2's to .88-.91. I had to set my WOT to 14% lean on the MAFT to achieve an average of .89.

Put it on the dyno, and AFR was running dangerously lean, like high 14's at least. We reset the WOT to +0, and the AFR's came back into line. It ranged from 12.7 <-> 13.1 from 3500 -> 6500. A little too rich above 6000 and a little too lean below 3500. There was a 30RWHP difference between those two runs. My O2's read ~.93-.94 for an ~13:1 AFR.

Even though the lid says it isn't used, I had to set my base to +5 to get my LTFT's in negative single digits. It made a difference from the +4 setting.