SleeperZzZ

Hey, i just bought an autometer Air fuel ratio gauge. Right now i have it hooked up to the light for the cig. lighter. When my lights are on it gives me a diff. reading then when there off. So if you have one could you tell me where you wired it to, and how good it works. thanks in advance

andrewb70

Did you wire it to the O2 sensor as well? There are 3 wires on it. Ground, power, and sensor.

Andrew

SleeperZzZ

yea its wired to the o2 sensor, just when i turn on the lights i get a different reading, and i know my car doesnt run different becuase my running lights are on.

Lights off = rich
lights on = a lil twords the lean side
that is sitting in a stand still idle.

NZConvertible

A/F gauges should be wired in at the ECU. You can access power, ground and signal wires in one location.

SleeperZzZ

this may be dumb, but how do i access power from the ecu

Wankel7

did you use the power that goes to the light of the cig. lighter? or the lighter its self

James

NZConvertible

The ECU has power going to it. That's what makes it work...

silverrotor

iTrader: (1)

Follow this link. I used this route.

https://www.rx7club.com/forum/showth...ht=a%2Ff+ratio

SleeperZzZ

ok well the ecu seems like an easy way, but i have mine all connected, i got power from my cig. lighter light. and grounded with my cd player, and went straight from the o2 sensor. i just wanted to know, if having it powered by the light will affect my reading, because when my lights are on i get a diff. reading.

SleeperZzZ

the power that goes to the lighter light

NZConvertible

That's only live with the lights on! You need to find a wire that's live any time the ignition is on.

You shouldn't tamper with the O2 sensor wire in the engine bay. There's too much risk you'll touch the braided shield around the signal wire and ground the whole thing. Then you'll have no A/F gauge and no signal to the ECU. Always go straight to the ECU.

SleeperZzZ

ok ill move the wire to something live when the car is on, but my wire in the engine bay for my o2 sensor, wasnt sheilded. is that a problem?

Wankel7

Not sure....if that is a problem.

Yeah, that cig light power is on a reostat. So when you dim your lights the voltage drops.

If you are planning on doing much more electrical work you might want to buy a Factory Service Manual. It has a complete wiringing diagram. I am not talking about hayes style either. It is 90 pages with pull outs and colors.

I had one when I did my gagues. I believe I used a 12V IGN source that runs into one of the controls in the instrument cluster.

Just a thought for everybody else....are power wires genrerally the same color? I don't have my FSM with me....

James

Kanaida

or get a phatty guage that comes with its own 02 sensor. To be honest, I thought all a/f guages came with their own o2 sensor.. But obviously they don't, and that sucks. Return that bad boy and buy a Greddy.

-Kanaida

Wankel7

Or return it and build a wideband oxygen sensor kit.

Which leads me to my next question.........

U are not using gauge for anything more than a light show and to make sure your feedback system is working right?

James

tmiked

What is the A/F ratio when you are heating up the lighter ?

Kanaida

I just have mine to show off to the ricers. ****, I see kids without forced induction running a/f guages (with funky lights all over!) and I don't want to be shown up by THEM!

-K

westcoasttuner

Ok so is a AF guage worth it? I would like to know if I am runnin lean will it give me a clue or just a light show? I have a 87 TII...

seventhgear

sleeperzzz....
whered ya get the gauge? was it brand new?
jack

Kanaida

Yes, an a/f guage would give you a clue if you're running lean. But it is not accurate enough to precicely tune your engine by. Of course, you should tune with a wideband o2 sensor. But if for instance, you have injector failure, or your injectors start leaking or whatever, then yeah, it will give you a basic idea that you're running lean/rich.

-K

westcoasttuner

Cool Thanks.
How would I get a wideband O2 sensor?
Please forgive my ignorance but never have came across one...

SleeperZzZ

The air fuel gauge is to tell me how my car is running, but mostly for the lil show it gives...hah.... jack i got it from auto zone, its an autometer. right now the gauge isnt my worst problem. Now i dont have a tranny

Kanaida

uhh... you don't want a wideband.. It's basicly only to be used for tuning. It's 1000 bucks. Tuning shops will have them, so if you paid a shop to dyno tune your car, they'd drop a wideband in your exhaust and then tune it. You don't want to have it sit in your car 24/7 like your normal 02 sensor. That'd be a waste. Only use 'em for tuning. Unless you have a serious serious race car, and tune non-stop.

-K

Wankel7

I built my wideband from Techedge. Search for Techedge and wideband.

EVERYTHING (Stuff to build it, tools, sensor, kit, weld ring welding, blah blah) $325.

You can leave it in your exhaust till the wheels fall of your car if you choose. Nothing wrong with that. The sensor came out of a Honda Civic VX 3door 93-95.

James

NZConvertible

Those are still not nearly as good as the $1000+ units the dyno operators use.