Need guidance for begining to tune

[Moonbiter]

Here is a scan of my car just cruising around and WOT from 0-60. The information I'm looking for, is where to begin. Should I adjust my MAF table because I have an aftermarket air intake, or do I need to look elsewhere? I seem to be running lean for the most part in both scans but I have no idea where to start. Could someone give me a nudge on where to start looking?

Temp was about 96 to 98* outside with high humidity. I live in MO and it's normally hot and humid in the summer.

Thanks.

Cruising
WOT 0 to 60

[Moonbiter]

If I create a histogram with MAF (hz) vs LTFT and I see lean areas, does that mean I need to add positive numbers to my MAF table or subtract from it? Is this the right approach to begin to tackle my tunning problem?

[5_Liter_Eater]

That is the first place to start, getting your airflow in line. If you don't have a wide band that means tuning with fuel trims. You're well on your way if you've already got a histo together that plots the LTFTs against the MAF table. Basically all you need to do is copy and paste those numbers (paste special, multiply by %) into the MAF table in the editor. If you have a negative fuel trim in one Hz cell then that means the PCM is having to remove fuel from that portion of the MAF curve in order to maintain stoich so the MAF curve needs to come down by that %.

A couple things: Stay out of PE. In PE your fuel trims lock out and the data is no good to you. You can go so far as to put a plot filter on the histo to filter out any PE data. [SENS.121]<14.6 You need to be logging commanded AFR for this filter to work. Remember to clear your fuel trims in-between logs and flashes. Once you get close you can start multiplying by %-1/2. You will not be able to hit the upper part of the MAF curve since you will be in PE at that point. You need to get a WB for that. But if you notice that the vast majority of the data you're collecting is, say, +10 then you could probably safely just increase the whole MAF curve by 10%.

HTH

[Moonbiter]

Thanks, I get the PCM back tomorrow and I have the histogram already set up, so I can try that out. Thanks for the nudge.