Air Fuel Ratio Gauge

[smoky723]

ok i bought an air fuel ratio guage by autometer and i was wondering how to install it i have installed one on a supra befor u just wire it to the o2 sensor.. but i tryed that on mine the digital needle just goes crazy all the time except for wen i slow down.....i no you guys are gunna say it been posted yeah it was posted befor but no one answered

[rusty9]

if its a 4 cylinder i do believe you need to wire it to the vF signal at the ecu or one of the diagnostics ports. if its a v6 then you'll have a vF1 and a vF2, one for each cylinder bank. dont ask me how to calibrate it tho

[smoky723]

were do i put it on the ecu for a 4 cylinder

[rusty9]

well, the ecu is behind the glove box. so i would suggest using the diagnostics port under the steering wheel since its labeled. it would be much easier to get under there to splice in a wire then ripping out half your dash.

[smoky723]

ok which wire do i splice my diagnostic is under the hood

[Silver Streak]

That's all it's supposed to do...bouce back and forth, back and forth...like KITT's red red. It'll obviously show rich during WOT, and during decceleration, it'll have some other readings as well....

[rusty9]

like i said, splice the vF signal wire. the port under the hood is labeled too.

[smoky723]

ok well Silver Streak thats what it does but some times at WOT it goes a little down to lean and i dont see the vF signal wire label anywere

[Toysrme]

You don't use the vF wires on an A/F gauge. vF is a 0-5v signal OBD-I ECU's output to show fuel trim. Not o2 data.

For o2 data, splice the o2 sensor wire<s>.

Tho vF data can be extremely handy when combined with o2 output, you can't substitute it.

[camrykidd86]

I just hooked mine up today, but the splices didn't work at all that came with the kit.. pisses me off, but yes, splice wire thru the o2 sensor wire um I can't remember what color everything is, but I can hit his back up tomorrow and tell you everything, but the headlight switch in the steering colum is Red with a blue stripe.. all I can remember.. thats for the 94 I'm not sure what year yours is, you should buy a Chilton manual if you dont' alraedy have one, great great great wiring diagrams

[Zandro]

You need a wideband o2 sensor for the A/F gauge to work properly
or else the gauge wl only flip between lean and rich

[DarkMastyr]

^+1

Without a wideband, A/F gauges are useless.

[RedPhoenix]

be like me. ask for a $300 aem wideband for christmas

[ModifierMR]

when i had a Air Fuel Guage i tried hooking it into my oxygen sensor and never got it to work.... My car's 02 sensor had 4 wires coming off it, 2 Black, 1 Blue, and 1 White.....i used voltmeters to try to find the right one, but i never did.

[Ken4]

Look for the OX1 terminal on the ECU. Connect your $10 multimeter there and one to the ground, and there you have it, a home-made AFR meter.



During closed looped (idling, low load) the voltage will fluctuate all over the place, .i.e. 0.3v~0.7v, which means the AFR is very close to stoichiometry 14.7. During open loop (aggressive driving), the voltage stabilizers around ~0.88v which means AFR is around 13.3. Use this chart as a reference.

http://www.zeitronix.com/questions/O2questions.htm