A/F ratio at Idle?
#1
A/F ratio at Idle?
I'm not sure if I imagined this, but IIRC my zeitronix read-out used to be 14.7 A/F when the car was idling. It would fluctuate up and down but would always stabilize. But the unit was always half-way covered and after awhile I stopped paying attention
However now that i've relocated the zeitronix unit to a more noticeable location, the screen reading shows that the car idles at 14.0 A/F and fluctuates around that point. At WOT, the A/F is incrementally lower also. In the past, 3rd gear at 7000 rpm was 12.2 A/F and now it is 11.8 A/F
At first I thought it might be the LCD screen, but I plugged the zeitronix unit directly to the labtop and it shows the same readings.
Can anyone with a WB02 confirm their A/F readings at idle? I was thinking that the ECU should automatically adjust for temperature changes.
However now that i've relocated the zeitronix unit to a more noticeable location, the screen reading shows that the car idles at 14.0 A/F and fluctuates around that point. At WOT, the A/F is incrementally lower also. In the past, 3rd gear at 7000 rpm was 12.2 A/F and now it is 11.8 A/F
At first I thought it might be the LCD screen, but I plugged the zeitronix unit directly to the labtop and it shows the same readings.
Can anyone with a WB02 confirm their A/F readings at idle? I was thinking that the ECU should automatically adjust for temperature changes.
#5
No, the zeitronix doesn't have auto-calibration. They told me to send back the unit, lcd, and o2 sensor for testing. That is going to be a pain un-installing everything.
I'm wondering if the wbo2 went bad or if something is wrong with the ECU
I'm wondering if the wbo2 went bad or if something is wrong with the ECU
#7
mine settles typically between 14.7-14.8 at idle after its warmed up. even though it may not have stuck, i have 8% fuel taken out at idle and up to 11% during partial throttle. i can see that return being a pain but definetely worth getting figured out.
#8
Originally Posted by sloppymax
mine settles typically between 14.7-14.8 at idle after its warmed up. even though it may not have stuck, i have 8% fuel taken out at idle and up to 11% during partial throttle. i can see that return being a pain but definetely worth getting figured out.
#9
Originally Posted by steven88
i thought changing the part throttle settings won't do any good?
#10
Originally Posted by sloppymax
it will typically revert back but i left the settings and it is not doing any harm.
and when you say "typically"...out of how many times will it go back...and how many times it won't?
#12
Originally Posted by steven88
so what afr are you at with the current -8%?
and when you say "typically"...out of how many times will it go back...and how many times it won't?
and when you say "typically"...out of how many times will it go back...and how many times it won't?
#13
I have it right before the cat. It worked fine as long as I can remember. But for some reason now its only 14.7-14.8 cold start and then keeps dropping down to 13.8-14.0 warmed up.
Its annoying because WOT is reading pig rich, I datalogged 11.5 A/F ratio this morning. Zeitronix told me to pull the whole unit and send it back for testing. Thats going to be a big pain
Its annoying because WOT is reading pig rich, I datalogged 11.5 A/F ratio this morning. Zeitronix told me to pull the whole unit and send it back for testing. Thats going to be a big pain
#16
I used the OBD-II scanners, the car has no codes. The voltage and fuel trim "look" okay for the primary o2's (although i'm not sure how I can tell they went bad).
I purchased a new bosch wideband o2 to see if the sensor went bad. My gas mileage has been around 26.3 mpg, so I ruled out the o2 sensors going bad
I purchased a new bosch wideband o2 to see if the sensor went bad. My gas mileage has been around 26.3 mpg, so I ruled out the o2 sensors going bad
#17
Originally Posted by steven88
then what are you running if you put it back to 0%?
#18
I must have used a bad batch of gas (or accidentally filled up on 87 octane).
The idle A/F is back to 14.7
I had to fill up the last two times previously at a no-name gas station during a business trip.
The idle A/F is back to 14.7
I had to fill up the last two times previously at a no-name gas station during a business trip.
#19
I notice a diff when a gas station is trying to pull off a scam selling 87 as 93 octane. My AF hangs around 14-14.2 on the cheap stuff and runs in the mid 12s under WOT. With 93 my car idles around 14.8-15.0 A/F. Under WOT I see 13.6:1 . I use PLX M300 that I've had for over a year, 155k mile Original 02 sensors also.
#21
Originally Posted by BlackBIRDVQ
I notice a diff when a gas station is trying to pull off a scam selling 87 as 93 octane. My AF hangs around 14-14.2 on the cheap stuff and runs in the mid 12s under WOT. With 93 my car idles around 14.8-15.0 A/F. Under WOT I see 13.6:1 . I use PLX M300 that I've had for over a year, 155k mile Original 02 sensors also.
My a/f under WOT was into the 11's at the time
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