AFR Fluctuates Badly?

[mikeyayell]

I have a FAST wideband and my wideband is 14ish at warm idle and goes to the upper teens even the 20s after a minute of idling and does the same at part throttle sometimes. I keep ttrying to tune it and when it feels and runs good the wideband says its not. ANy help greatly appreciated.

[5.7ute]

Post up your log & tune so we can have a look.

[mikeyayell]

Tune and log.

[5.7ute]

I dont have the pid for a fast wideband. Could you also post up your Calc pid txt file.

[mikeyayell]

#Parameter Value Description
#---------- ---------------- ---------------------------------------------------
VERSION 7.1.1 File version
DECSEP . Decimal separator used in this file



# ================================================== ============================
# Units
# -------------------
# See sae_generic.txt for more information on the *UNITS section

*UNITS

#Code System Abbr Description
#-------- ---------- -------- -----------------------------------------------------------

PSI Imperial PSI "Pounds per Square Inch"


# ================================================== ============================
# Add slot definitions here
# --------------------------------
# See sae_generic.txt for more information on "SLOT" formats
#
#Units Low High Fmt Expression
#------------ ------------- ------------- ---- --------------------------------------------------------------

*CLC-00-998
%rich -20.0 20.0 .2 "({SAE.SHRTFT1}+{SAE.SHRTFT2})/2"

*CLC-00-999
%rich -20.0 20.0 .2 "({SAE.LONGFT1}+{SAE.LONGFT2})/2"





# Fast WBO2
# ========================
*CLC-00-985
V 0.0 5.0 .1 "{EXT.AD1}"
AFR 10.0 20.0 .2 "{EXT.AD1}*2.78+9.6"
*CLC-00-984
factor 0.0 2.0 .1 "{CALC.AFR_FAST1.AFR}/{GM.AFR}"




# Replicate wide band setup for LS2 style GM.AFR_B PID
# ================================================== ======================



# Fast WBO2
# ========================
*CLC-00-977
factor 0.0 2.0 .1 "{CALC.AFR_FAST1_LS2.AFR}/{GM.AFR_B}"



# ================================================== ============================
*PRN - Parameter Reference Numbers
# --------------------------------
# See sae_generic.txt for more information on the *PRN section
#
#Code PRN SLOT Units System Description
#------------------------- ---- ------------ ---------------- ---------------- ------------------------------------------

CALC.STFT_AVG_B1&B2 F600 CLC-00-998 %rich Fuel "Average STFT1 & STFT2"
CALC.LTFT_AVG_B1&B2 F601 CLC-00-999 %rich Fuel "Average LTFT1 & LTFT2"




CALC.AFR_FAST1 F618 CLC-00-985 "AFR,V" O2-Wide "Wide Band AFR 1 - Fast"
CALC.BEN_FAST1 F619 CLC-00-984 factor O2-Wide "Base Efficiency Numerator 1 - Fast"



CALC.BEN_FAST1_LS2 F609 CLC-00-977 factor O2-Wide "Base Efficiency Numerator 1 - Fast _ LS2"

[mr.prick]

look at this thread.
http://forum.efilive.com/showthread.php?t=6159&highlight=leanness

[5.7ute]

First thing is you have no wideband input into your log. If you are trying to tune with auto VE you will need to get that sorted.

[mikeyayell]

I am talking about when I just have the wideband hooked to the car without efilive.

[mikeyayell]

Wideband is new so I dont think it could be the sensor Mr. Prick. WHat should the LTFTs be reading for a good AFR? Maybe I can check it that way.

[SSpdDmon]

I'd question the formula. What is 5V supposed to represent? 0V?

Because right now, the formula is set so that 5V=23.5:1 and 0V=9.6:1 (4.096V=21:1).

*EDIT*






• Simple Mode: This takes the output voltage and multiplies it by 10 to calculate the actual air/fuel ratio. Many external electronic air/fuel gauges use this signal type.







• High Res Mode: This provides a 0 - 4.096 volt output signal. Certain digital gauges and data acquisition systems use this type of signal.






• Narrow Band Simulator Mode: This provides a narrow band output signal that simulates many OEM style air/fuel sensors. This will allow you to use the wide-band style sensor the FAST™ Air/Fuel Meter uses not only to serve the air/fuel meter, but to also run the engine’s computer. This mode is compatible only with pre-OBDII vehicles.





http://www.fuelairspark.com/Instructions/170450.pdf page 4

[mr.prick]

did you change the tune?
you will know if you are running lean,
the car will sound choppy.
also i fixed the link above.