Air/Fuel gauge install

GTCobra90

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Dec 29, 2005
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hey everyone, im needing a air/fuel gauge and it says to locate my sending terminal wire. i have a haynes and a chiltons but i can't find were it tells me which wire is which. wich wire do i use or can you point me in the right direction in my manuals. thanks

i have a 1990 GT it has two white wires, one blank and one grey, there bosch.
 
By "needing an air/fuel gauge" I assume you are looking for a Wideband. Correct?

If thats the case then a regular O2 sensor will not do.

Most good aftermarket Widebands come with the new sensor.

There are some A/F gauges that are Narrowband and are nothing more that a light show.

A little more info is needed.
 
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.

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

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 have a stewart warner gauge and the instructions say to find the sender terminal wire from the O2 sensor from the vehicles wirring harness and not from the actual sensor wire. i just can't figure it out off of my manuals.

right on thanks jrichker. i should probebly buy a wideband setup then. is the ennovate LM-1 a good setup?
 
sweet!!!

thats good then. i will be ordering one of those soon. does anybody know where to get the best deal for one? i found one on ebay slightly used from the company for $170.
 
The gauges for WB's are pretty pricey. Ensure what you're looking at includes a gauge if that's what you desire.

Good luck.
 
the setup im looking at doesn't come with a gauge and they are pricey. it comes with the program for a computer though so would i be able to use my laptop for the same purpose just to tune my car? later on i could get a gauge but for now if it would work i would just use my laptop to tune it.
 
If you want to hook up that just tap into pin 29 or 43 like Jrichker says and I have used a SPDT to switch between the two and is kinda cool and easy to do.

As for a Wideband setup I have a PLX DM-100 setup and Love it.....fully digital, all different gauge backgrounds and you download your own backgrounds if you want, it's pretty slick. It's on www.plxdevices.com
 
the setup im looking at doesn't come with a gauge and they are pricey. it comes with the program for a computer though so would i be able to use my laptop for the same purpose just to tune my car? later on i could get a gauge but for now if it would work i would just use my laptop to tune it.

http://www.theturboforums.com/smf/index.php?topic=77263.0 This has information on building an A/F meter on the cheap, you still need the wideband & something you can set outputs on, like an lc-1.
 
The gauges for WB's are pretty pricey. Ensure what you're looking at includes a gauge if that's what you desire.

Good luck.

The LM-1 has a 1V analog output specifically for your run-of-the-mil AFR gauge. You can use any off the shelf gauge and plug it into the port with the supplied cable. The LM-1 will make your gauge "accurate".

AFR gauge hooked to a narrow band (stock) sensor = Useless
 
Andy, good info. :nice:
I had come across such a set-up (I think Millhouse used to have one). But how do you know what exact ratio you're seeing? Otherwise it would seem the gauge is kinda useless, no? Or maybe there is a way to interpolate the LEDs (and make a homemade bezel which has the ratio at that LED location)?

It's an interesting idea. :nice: Is it worth really pursuing?
 
I have the LC-1 that I am installing now and I have a Speedhut gauge in the car.

But I will be using mostly with my SCT XCal 2 and laptop to datalog. The gauge is just there to be able to glance at and has a built in warning light in case it starts to run lean. (Which can be set to whatever A/F number you want.) In my case with a boosted application I feel 11.4:1 is where I am tuning my car for in WOT.
 
Andy, good info. :nice:
I had come across such a set-up (I think Millhouse used to have one). But how do you know what exact ratio you're seeing? Otherwise it would seem the gauge is kinda useless, no? Or maybe there is a way to interpolate the LEDs (and make a homemade bezel which has the ratio at that LED location)?

It's an interesting idea. :nice: Is it worth really pursuing?


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I guess that it would wholly depend on the gauge that you used. Something with general indications on it would only give you an "at a glance" idea of whether you're in the safe zone or not. Others might have an actual digital readout to pinpoint your current AFR.

What the LM-1 does to accommodate these narrow band AFTR gauges is convert the wide band signal into an accurate 1 volt reference. So instead of getting just an off-scale high, off-scale low, or stoich indication, you get an actual READING of your current AFR. So long as the gauge is in good working order (as well as the LM-1, of course), then the needle reference will be very accurate. The ability of the gauge to convey an actual AFR ratio to the reader... that would depend on the layout of the gauge (kind of like how detailed a reading you can get form a compass. The needle will still point north regardless of how crappy the thing is. hehe).

Now, if you're looking for something that is going to be both accurate (direction of pointed needle) as well as give accuracy in reading, I'd go with something like this Greddy gauge:

3033_3lo.jpg


These things are pretty pricey (think $250 or so). By the time you get a wide band and purchase this gauge to accompany it, you might as well have bought a system that comes with a gauge.

Still... I really like this Greddy gauge. It matches well with my fuel pressure and Vac-boost gauges (which are also white faced and amber back lit). It seems like it's getting harder and harder to find analog gauges that show accurate and usable information (no digital for this kid).
 

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Andy, thank you sir. I've been waiting for prices to come down (which they have in the last few years). I'd like to have a gauge just to see if something goes weird, or I need to try and change something a little (I have a Moates chip in the 94). Am I correct that the LC-1 would not be able to convert the 5 V signal to a 1V signal?

Kevin, the gauges are hot man! I like the mix (I think having indiglo-style gauges would annoy me in a pillar so I really like your blend). :hail2:

GTCobra, apologies for the tangents. I normally don't do that but I felt that the stuff I was askin might be of interest to you as well.