A/F Commanded 11.74

[cartman003]

Hey everyone,

I was tuning an 07 Legacy truck (FlexFuel, DOD) I was tuning the MAF and put the car into open loop as well as set all the OL value to 1.00.

On a 07 Corvette that allowed me to pretty much isolated the AF to whatever the PE was commanding, but on this truck it always revert to 11.74. What gives?

I have attached the log and file, because at this point I'm not quite sure what prevented the car to command what is in the PE table.

The other thing you will notice from the log is that when the car is at idle it's commanding 13.69 which was another issue that I could not quite figure out. At first I thought it had to do with the fact that maybe some ethanol was detected in the gas and was commanding a richer A/F but after playing around with the Stoich table it didn't really make a difference.

[Bill@HPTuners]

Definitily looks like the stoich table is skewing all of your numbers, remember you have your pe set to 1.16 so 13.69/1.16=11.8:1 roughly.

[BBA]

Bill, that brings up a question: The stoich table is used for flex fuel right? So if the O2 sensors are switching, it's at stoich no matter the fuel mix and the PCM and sensors determine what stoich table to use based on that?

As well, the PE AFR is going to be the current stoich table value in use divided by the PE multiplier?

I guess it doesn't matter so much for my car since it if not a flex fuel car but just to know how it fits in I thought I'd ask.

[ls14camaross]

hey go under closed loop and change your o2 readiness to a higher number liek 284 or something

[cartman003]

Definitily looks like the stoich table is skewing all of your numbers, remember you have your pe set to 1.16 so 13.69/1.16=11.8:1 roughly.

Bill,

That makes sense, but I also set the first two breakpoints of the stoich table to 14.7 and I modified the PE table to 13.0 and still only saw 11.7 commanded. I know around here you can't find gas with more than 10% of e-85.

[cartman003]

hey go under closed loop and change your o2 readiness to a higher number liek 284 or something

The vehicle has been placed into open loop; so the closed loop parameters would be ignored. BTW, why would you change it to 284?

[Bill@HPTuners]

Please try this file and if you still are getting a commanded afr of ~13.5:1 at part throttle please post a new scanner log.

[cartman003]

Please try this file and if you still are getting a commanded afr of ~13.5:1 at part throttle please post a new scanner log.

Thanks Bill. I will post my results once I get the truck back.

[ls14camaross]

The vehicle has been placed into open loop; so the closed loop parameters would be ignored. BTW, why would you change it to 284?

284 im just so used to ls1s but just max out the number. plus it seems to work cuz bill did it