Car goes from Fuel source 0 or 5 to 2? Why?

[kxt]

We doing a slow sweep in 4 gear the car will go from fuel source 0 to 2 at about 490 AD COUNTS. In a WOT situation the car will go from fuel source 5 to 2 at about 883 AD COUNTS. Why does the car go into source 2??? Advantage datalogger says fuel source 2 is used when an exhaust component is too hot... how does it read this?

 

[kxt]

still needin' some help.

 

[kxt]

Datalog Files:

http://www.quia.com/files/quia/users/jmbutler/full.csv
Includes a WOT test

http://www.quia.com/files/quia/users/jmbutler/swep2.csv
Includes RPM sweep slowly

 

[workmangc]

AFAIK, fuel source is indication of open loop or not.

 

[kxt]

^Yes
Fuel Source 0 = Closed Loop
Fuel Source 5 = Open loop (WOT)
Fuel Source 4 = Start up mode
Fuel Source 2 = Open Loop because an exhaust component has become too hot


The problem is I don't know how exhaust temp. is determined to understand why the car goes from fuel source 0 or 5 to 2.

 

[workmangc]

I'm not sure on this one. As strictly a guess, perhaps it is some sort of input from the O2 sensor???

 

[kxt]

That's what I am thinking but I'm hoping someone who has had experience will chime in. I could understand it more if the car was running real lean, but as you can see from the logs its not.

 

[CAPONE]

Curious...Does your cars still have cat's?

 

[kxt]

no cats

 

[CAPONE]

My guess...

In the fuel scaler, there's a switch for cat temp that's available on Cobra's and late GT's. When the scaler is set to a value of 1, it's active & will add extra fuel to cool the cats. When this happens, you'll notice a mysterious richening at WOT. I see your STFT's at WOT indicated ~ 11.5 afr, when @ #5 fuel source...Once fuel source went to 2, you got really rich ~10.5.

Assume analog signal was your w/b...So I can apply your w/b transfer, what kind is it?

 

[kxt]

analog 1 is a dynojet WBC
Analog 2 is a afx w/ ntk sensor

 

[workmangc]

My guess...

In the fuel scaler, there's a switch for cat temp that's available on Cobra's and late GT's. When the scaler is set to a value of 1, it's active & will add extra fuel to cool the cats. When this happens, you'll notice a mysterious richening at WOT. I see your STFT's at WOT indicated ~ 11.5 afr, when @ #5 fuel source...Once fuel source went to 2, you got really rich ~10.5.

I had done some research on this and saw that it was to cool the cats also. So.....assuming that if he has deleted the cats he should set it to 0 to disable the fuel change?

 

[kxt]

thanks dude