Air-Fuel Gauge

[Auto Reverse]

Can anyone tell me what wire off the O2 sensor I need to tap into for my air-fuel gauge to read?

I have MAC long tube headers. Thanks.

 

[BaXTeR3221]

no offense, but those gauges don't do anything unless you have a wideband. Do you?

 

[Auto Reverse]

Not yet, it's in the budget for next year, but I at least need something, even if it's not as accurate as a wideband.

 

[jrichker]

Use 43 (Dark Blue/Lt Geen wire) or pin 29 (Dark Green/Pink wire ) on the computer. Use Wire tap-ins from Radio shack P/N 64-3052. The computer is located under the passenger side kick panel. That keeps you from having to crawl under the car and make a weather proof splice in the wiring. You can use either one, or run a SPDT switch and use both. Then you can use the switch to select which side to view.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/t...91eecPinout.gif

The A/F gauges that use the O2 sensor signal will jump all over the place. The reason is that the O2 sensors "switch" between .2 volt lean and .6 volt rich with a curve that looks like the drop off a high cliff. The curve is almost straight up and down, so the voltage shoots from .2 to .6 and back down . again 2 or more times a second at cruse. You won't get much useful information except when the mixture is extremely lean or extremely rich, there is no middle ground.

AutoZone wiring diagrams

http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp for 89-93 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-98 model cars

 

[Mike92GT]

Use 43 (Dark Blue/Lt Geen wire) or pin 29 (Dark Green/Pink wire ) on the computer. Use Wire tap-ins from Radio shack P/N 64-3052. The computer is located under the passenger side kick panel. That keeps you from having to crawl under the car and make a weather proof splice in the wiring. You can use either one, or run a SPDT switch and use both. Then you can use the switch to select which side to view.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/t...91eecPinout.gif

The A/F gauges that use the O2 sensor signal will jump all over the place. The reason is that the O2 sensors "switch" between .2 volt lean and .6 volt rich with a curve that looks like the drop off a high cliff. The curve is almost straight up and down, so the voltage shoots from .2 to .6 and back down . again 2 or more times a second at cruse. You won't get much useful information except when the mixture is extremely lean or extremely rich, there is no middle ground.

AutoZone wiring diagrams

http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp for 89-93 model cars

http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-98 model cars

I wired mine up just like Jrichker described above. I tapped into both O2 wires by the computer and ran them to a toggle switch so I can switch between left and right bank. As stated, these guages do jump around a lot and are not that accurate. On the up side., I actually used mine to diag a bad O2 sensor. My check engine light came on one night, and I noticed that when I switched between o2 sensors, one of them wasn't reading hardly at all on the guage. I replaced them both for good measure, but had I wanted to replace just one I would have known which one it was.

 

[Mr. Potato Head]

It's not that they are "not as accurate" as a wideband, it's that they don't do anything. It's just a light show. A narrowband is good for nothing except at idle. So save your money on a narrowband and put it towards your WB budget.

 

[86bluecobra]

how expensive are these widebands?

 

[Daggar]

I paid $325 for my Innovative LM-1. They may be cheaper by now.

 

[Daggar]

http://cgi.ebay.com/ebaymotors/Inno...ewItemQQcategoryZ43989QQitemZ4595964458QQrdZ1

 

[86bluecobra]

sweet i want one i need to have my carb tuned properly i know it runs rich.

 

[351LX]

I once hooked a single wire narrow band O2 sensor into a bung I welded into my exhaust and hooked a voltmeter set on the 2v scale and found it very helpful for tuning purposes.It allowed me to quickly get into the ballpark I needed for jetting and then I could fine tune after that.You aren't going to be able to use it to tune for maximum power but it can get you close.The voltage didn't jump around significantly as long as I kept a steady foot on the accelerator pedal.The narrow band oxygen sensors are designed to produce a voltage output of approximately 0.5 v at around 14.7 to 1, anything voltage higher than that is rich and lower is lean.They require no input voltage as they generate their own voltage.I recently bought a wideband so I could measure air/fuel ratios accurately below 14.7 to 1 but if you understand the limitations of the narrowband ones they are still useful.

 

[rockyracoon]

well from experience with my turboranger,the a/f gauge seemed to be somewhat useful by letting me know if I was getting into closed loop cause it would bounce,kinda stoic like,and it seemed to help to indicate if I was going lean when under boost.JMHO

 

[351LX]

My experience with the single wire oxygen sensors is with carbed motors.From what I understand about fuel injected motors the computer is constantly going from slightly lean to slightly rich to obtain a happy medium so that might cause more of a problem with an air/fuel gauge.