How to read Air Fuel Ratio Meter?

[evo3]

Hi,

Need help on reading A/F Ration...hehehe...

Yesterday i install a A/F Ration meter, and it doesn't show any reading when idling..no light indicator but when the car is moving and u release the gas pedal then it will onlt show the reading...it tat ok or that is something wrong? :P

Thanks

 

[CcL]

ehhhhh
as long as the O2 sensor is warmed up there should be a reading
even when the engine is off!!
check the wirings...

 

[evo3]

i have check the wiring....it is ok...cos only one wire to the O2 sensor.....is the wire that i use not suitable cos i using the Red/Black wire...but i use one piece only la....hehehe

 

[DRFT_240sx]

well i assume u are using a narrow band O2 sensor , when during idling open loop it should be bouncing up and down...

when driving/cruising in close loop then u will have indication of where your a/f ratio is ( this is during WOT).

no point to invest in a narrowband , just for display only.... the one that actually indicates if you are running rich/lean is wideband O2 sensors.

cheers

 

[cmng]

narrow band is better then nothing
at least you get some figure

Wideband.
only rich boy will drive and use wideband AFR meter all the time
:)

 

[acbc]

Yeah... feel like removing my AutoMeter A/F Meter and put it up for sale soon...

 

[evo3]

hehehe..wide band too expensive...i install it for the reading when the boost start to kick in.....hehehe

Yeah...when idle , it should bounce up and down but this a/f meter, show no reading....it only show reading when i release the gas pedal or when the boost start to kick in...hehe...

Oh yeah..i tap the signal from the sensor at the exhaust manifold.....or i should tap the signaL from the ECU? :P :D

 

[alvin24]

Actually first thing is you should mention what brand airfuel ratio u've installed.

If its autometer... during idling it shold be bouncing up and down. During acceleration it should be reading rich.... and deceleration it should go down to red... if u're maintaining speed, it should be bouncing up and down as well... (assuming healthy fueling conditions).

Maybe other brands got other readings? Hahaa...

If its always on red... means either your O2 sensor kong... or the wiring got problem.

You'll need to warm up the O2 sensor first before u start getting readings.. else its always on red also.

 

[DRFT_240sx]

the warm up part i should say would only apply to a 3/4 wire O2 sensor... not those with single wire O2 sensor....

I would say no matter where you tap , close loop ( WOT) show your real reading , either in rich , lean or stoich , open loop then it is suppose to bounce up and down when u are not in WOT.....

cheers

 

[evo3]

oic....thxs

 

[ezwong2002]

ok.. that is the easy part to read A/F ratio via Autometer type gauge.. what about Apexi T/Timer A/F ratio? 14.6 <--- stoich, lean or rich? what i know is.. green (lean) red (rich) yellow (stoich) and how to set la the bloody thing? sighh...

 

[Joeker]

The brand or make of the A/F meter or gauge is irregardless.

Wat realy matters is the 02 sensor.

A narrow band 02 sensor oni reads stoich/near stoich (0.1~1V).

A wide band 02 sensor reads a broader band (eg. 0.01 ~ 2V). It will be able to show how much rich or mch much lean u are actually at.

My fren had his APEXi TT cum A/F meter benchmarked side-by-side with a MOTEC wide band A/D meter.

The result was APEXi was totally hopeless.

Therefore, to all u guys who "tune" your own cars with the aftermarket A/F meters using stock narrow band 02 sensor, please exercise a little caution.

Narrow band sensor cost about RM400. Wide band sensor is about RM3,000~5,000.

 

[evo3]

from wat i heard from my friend on Apexi TT reading is not "very" accurate .... if i not mistaken there is a disclaimer in the Apexi TT manual that say the reading are for reference only....hehehe :)

 

[acbc]

In other words, the A/F Ratio Meter is for deco purposes only la... :P

I'm using the AutoMeter A/F - feel like selling it off cheap already.

 

[Joeker]

Originally posted by acbc@Dec 8 2004, 11:02
In other words, the A/F Ratio Meter is for deco purposes only la

Not exactly so.

A stock engine operate at narrow A/F ratio anyway. So I guess the A/F meter although coupled with the stock narrow band 02 sensor, is displaying correct A/F reading as far as stock engine concern.

 

[stroker_kit]

but what if the Apexi TT tapped to a wideband O2 sensors, shouldnt it show u the right figure...after all, what matters is the signal supplied to the meter right??? plus APexi TT can set wat volt range for what AFR display...
secondly, ive compare my ApexiTT reading to the dyno graph lambda reading done at speedwork....the reading behaves similar at each rpm level, only less accurate....something like when the reading ia 12.0, apexiTT gives out 12.5..... honest to GOD im not lying.... or maybe Daihatsu's O2 sensor(denso) is quite accurate compare to others.... OR speedworks wideband sensor is not good enuf... heheh

 

[GT20v]

Originally posted by DRFT_240sx@Dec 7 2004, 10:15
the warm up part i should say would only apply to a 3/4 wire O2 sensor... not those with single wire O2 sensor....

I would say no matter where you tap , close loop ( WOT) show your real reading , either in rich , lean or stoich , open loop then it is suppose to bounce up and down when u are not in WOT.....

cheers

single wire O2 sensor need to wamr up...while 3 or 4 wire doesnt need to bcoz its already equip with heater while 1 wire depend on engine temp to warm it up....

for people using 3-4 wire...to make it warm real quick..let the key on the ON position around 5-10sec..this will give current to heater n warm it up b4 u actually start the car..


I find the autometer AF meter is very good...its not 100% accurate as a wideband but at least u know something about ur AFR...the disadv only it cant judge HOW lean or rich is ur AFRin unit.........its either lean or rich thats all....this is quite accurate....

if me....i wont trade or sell it at all.

 

[MitonCT26]

why la ppl always want to compare a cheap unit with a totally outrageously expensive unit?

apex`i TT imho is just for reference whether your O2 sensor is working fine or not ie. open loop running, fuelling during WOT.

if really want to tune it then rent the wideband sensor la...only about rm200 wat. no need buy mahal mahal stuffs to put into your car and run it. aiyo motec, microtech and haltech wideband sensor alone not cheap la...rm 2000 plus minus... :blink:

RM 2000 i can do many many things fren. just because one stock engine or mildly upgraded engine wanna see enough fuel or not go and buy wideband sensor... <_<

 

[DRFT_240sx]

well just suggesting to them.. not ask them to buy at all...

i myself is using an OZ unit from Tech Edge ... its always on the car to show me the reading.... *scared engine pecah , miskin ler * =)

 

[evo3]

hummm..... mine no reading while idling,it won't jump up or down.....hehehe...it will only show reading when the boost come in or when the gas pedal is release. Might my O2 sensor is not working properly anymore?

I install it cos i takut my engine pecah also..miskin liaw....cos this is the second engine ohhh.... :P