My A/F ratio

[bullet87]

My A/F ratio is at 13:1.1 at 4150 Rpm and my O2 volts are 129mv, whats wrong with this picture?

 

[Mike Licht]

depends, If you are at WOT it is REALLY lean, If you are crusiing down the highway at light throttle you are OK
Mike

 

[ijames]

And if you are using direct scan to get the afr and the maf is anywhere over about 245 it is not calculated correctly anyway. Give us some more info - are you trying to develop your own chip, using a wideband O2, dialing in a chip made by someone else, ...?

 

[bullet87]

I am dialing in a Max Effort chip, my MAF never went above 149 g/s. I am using a Direct Scan. Here is todays little test, all I did was take down the tip in to 0 instead of three and raised my spool up fuel 1 point.

Today's Yesterday's
RPM 3950----------------3925
MAF 149-----------------154
IAC 115------------------102
a/f ratio 9:8.1------------13:0.1
o2 volts 796--------------110

Hope this helps

 

[ijames]

Sorry, but I don't know anything about tuning up a max effort chip. Email Steve Y, or he may see this thread and jump in.

 

[TurboDave]

DO NOT, let me repeat, DO NOT ever use DS for reading A/F ratio. It has absolutely nothing to do with reality. As much as I love DS, and rely on it heavilly, there are some things in it that are just not realiable. A/F ratio is not a value pulled from the ECM, or even a value that the ECM calculates and sends down the data stream. It is strictly a value calculated by DS based on some pretty loose calculations the ECM is making.
Trust me it's not a reliable value to look at.
If you need to know an acurate A/F value, the ONLY way you'll read it is via a wideband O2 sensor.
As for what your O2's are reading, it depends on the quality of the sensor, it's age, how much lead fouling it might have been subjected to, etc. etc. and only then it's not terribly accurate or reliable if it's a swithing (regular) O2. Again, a wideband O2 is required if you're serious about getting accurate readings.