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Air fuel ratio gauge, is this normal ?????

  • Thread starter Thread starter Bad Saleen
  • Start date Start date Sep 7, 2004

Bad Saleen

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Jul 3, 2004
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#1
  • Sep 7, 2004
  • #1
When i run on the highway at 60 mph the light from the gauge dont stop to go up and down it s goes from 2 light in the red to the end of the green light in the rich is this normal and when i floor it it goes in the rich section 3 green light from the bottom, does my air fuel mix is ok

let me know
 

fiveotony

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May 20, 2001
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Gainesville, Ga
Sep 7, 2004
#2
  • Sep 7, 2004
  • #2
ok at wide open throttle it should peg out on the rich. When you are cruising it should move back and forth all the time at least mine does. If it starts moving very slowly from rich to lean or lean to rich your O2 is probably bad.
 

Bad Saleen

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Jul 3, 2004
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Sep 7, 2004
#3
  • Sep 7, 2004
  • #3
exactly what mine does i pop right 3 square inside the green and when im cruising it dont move slowly, the movement is fast
 

Ferocity02

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Sep 7, 2004
#4
  • Sep 7, 2004
  • #4
The PCM is constantly trying to maintain a perfect 14.7:1 A/F ratio. But it keeps overshooting so it bounces back and forth all the time, and it should. A/F gauges are only accurate at WOT though, and since they dont have any numbers on them, they can only be used to detect major changes in A/F as a result of tuning or mods.
 

mo_dingo

20+ Year Stangneter
Aug 26, 2003
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58
Tucson, AZ
Sep 7, 2004
#5
  • Sep 7, 2004
  • #5
Ferocity02 said:
The PCM is constantly trying to maintain a perfect 14.7:1 A/F ratio. But it keeps overshooting so it bounces back and forth all the time, and it should. A/F gauges are only accurate at WOT though, and since they dont have any numbers on them, they can only be used to detect major changes in A/F as a result of tuning or mods.
Click to expand...

Exactly. It's like a sine/cosine wave. Always oscillating between rich and lean during part throttle, with 14.7 as it's "mean".

I can't comment on how "quickly" the needle would go back and forth. But this is a sign that the O2's are doing their job.
Scott
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
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Sep 7, 2004
#6
  • Sep 7, 2004
  • #6
the o2's pulse several times a second.
 

stang_gt_1994

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Powder Springs, GA (30 min. from Atlanta)
Sep 8, 2004
#7
  • Sep 8, 2004
  • #7
Pules between 350mV-750mV @ closed loop.
 
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