Anyone encounter this before?

Evo 8, most recent tune this past September. Common upgrade path (stock motor, S1 cams and FP 71HTA, bolts ons, ID 1050X, AEM 50-1200 pump).
Same gas station I always use. Blend is very consistent regardless of summer/winter. Recent "test tube" spot checks have shown current fuel is consistent with past fuel.

With full tank (or near) WOT AFRs are lean (12.6-12.8 on gas scale). With low fuel level, AFRs are good (11.8-11.9). This is all totally repeatable, not a fluke thing.

*Zeitronix logs here* https://drive.google.com/open?id=18A...8LKH_X_V30vrP7

Possibly related: P0455 code that I began to notice occasionally after I switched to E85 in Dec '17.

In the event that you want to view the logs and don't have the software, it can be downloaded here. I prefer version 3.2.1: http://www.zeitronix.com/zdl/

 

Is your ecu setup to read the fuel temp sensor for speed density or a real iat sensor.

 

Negative.

 

That wasn't a yes/no answer question.

Is it set up to read the fuel temp sensor... OR ....do you have it setup for an actual IAT sensor.

 

Thanks, I guess I misunderstood that.

What I can tell you is that IAT is still being measured via the stock MAF.

Is my ECU setup to read the fuel temp sensor for speed density? No, still MAF based tuning on this car. ECU is still using Fuel Temp Sensor input as originally configured.

 

Do you have a way to look at injector pulsewidth/duty cycle during both scenarios?

 

Thank you for the suggestion. I assumed that since the calibration is the same in both scenarios that IDC is going to be the same. I will confirm that.

Just need to get Evoscan going. I've hesitated as I lose some of the sensors that are going to my Zeitronix nDash/ZT2 but I should be able to at least port the WBo2 over.