General Running lean at WOT

[Denji]

This post has been edited in hindsight to provide only important information.

Symptoms:

*All problems began after a refurbished alternator was put in my car (purchased from advance auto parts).

1. Interior and Exterior lights flicker intensely for 1-5 minutes on startup. This would sometimes be accompanied by a flickering battery light.

2. After initial intense flickering, lighter, less noticeable flicker remains that may not be seen unless its kinda dark.

3. Flickering occurs more intensely when decelerating in ANY gear.

4. Flickering occurs more intensely when above 3000 rpms.

5. Voltage fluctuated when measured with a voltmeter (headlights on, which tended to slow the flickering to be more measurable by my multimeter) between 13.5 and 16 volts. Measurments without a load on the alternator were inconclusive.

6. Wideband reading were lean, around 12:1 when WOT, without any adjustments. In order to richen it out to 11:1, around 8-11% fuel had to be added to my fuel trims.

 

[Denji]

Resolution.

I was told multiple times by different people including advanced that it was a bad ground. This was NOT true in my case. I checked all connections. In fact, I went to advanced auto parts and had them check my alternator and it came out good while in the car. They informed me that they would not replace the alternator under their lifetime warranty unless it TESTED bad by them. I removed it from the car and had it tested on their in house alternator tester. The shop manager informed me that I likely had a bad ground AGAIN and told me that the alternators voltage was just a little low, probably because of the "bad ground" I should have fixed that ruined it. He reluctantly replaced it after I complained.

After putting the new refurbished alternator on my car ALL of my problems went away. It was not a bad ground, it was definitely some problem with the alternator controlling voltage (voltage regulator) or something. Everything returned to normal and car runs perfect without any symptoms. I hope this helps someone so they don't have the headache I did, but, if your dealing with advanced autoparts I wouldn't count on it.

[RESOLVED]