air/fuel ratio good or not good

[Ninja_tune_factory]

hi all...............................

im finking about get one for my R, id like to no wat ur thorts about the air/fuel gauges are like are they a wast of time or not.

thanks lionel

 

[Sirnixalot]

the greddy and apexi ones seem to be "accurate" but they hardly give you an idea of the exact ratio.

Fancy light shows is what i think they are. If you get a proper wideband O2 sensor and its controller like the Apexi UGEO or a TechEdge or similar which can tell you bot the actual ratio and the voltage which the O2 sensor is emmiting

 

[GINGA]

If you get one get one with its own dedicated lambda sensor as the ones that connect to the standard sensor are generally not accurate even my greddy one was 1.5 afr out on a proper gauge which could have been nasty imho a exhaust gas temp gauge would be a more accurate way of telling when your engine is about to melt :shock:

 

[sypher]

sorry for jumping in i would like to know if any figures are available even roughly for what engine ex' gas temp relates to what afr, and what afr relates to ex' gas emmisions as this seems to be every body keeps hush hush

 

[GINGA]

egt isn't just effected by afr its also effected by igniton timing, fuel quality, air charge temps etc and in reality you could call it a quality of combustion gauge
iirc a egt gauge show read about 800-900 degree on full throttle and around 400 degrees when cruising but I maybe wrong on that so if anybody knows the correct values please enlighten

 

[Mr GTiR]

Paul, those figures sound about right.

 

[Ninja_tune_factory]

so over all you all fink there a wast of time ?

 

[skiddusmarkus]

No they're not a waste of time.They work properly with a better lamda sensor though ie a wideband one.

 

[Ninja_tune_factory]

has any one used the autometer one as thats the one i was looking to get as it comes in carbon fiber .

 

[Edd]

I had autometer carbon fibre on the std lambda sensor...........what a waste of time :roll:

It kind of worked, ie went to full rich whenever you put throttle down and switched from lean to rich on part throttle but you only got those two options, full rich or flicking between the 2, however when it was cold it seemed to work better and actually registered across whole range.
Think with a proper sensor it'd be better but afterall it's just a pretty light show

 

[Ninja_tune_factory]

so wat wood u advise me to get ? as im looking for sumin that works right and is on point wen i driveing.

thanks for ur help evry one

 

[Edd]

get an EGT guage, as ginga says, at least you'll know when your engines about to melt :lol:

 

[mattygti-r]

i was looking at the prices for EGT guages and A/F guages from my supplier in Japan

Greddy 60mm peak hold a/f guage is foooooking expensive £200! or you can get a cheaper 52mm electric one...

EGT 52mm Greddy looks swish too,

i should be doing another Jap order next week,

 

[AJ4]

It kind of worked, ie went to full rich whenever you put throttle down and switched from lean to rich on part throttle but you only got those two options, full rich or flicking between the 2

Thats all its supposed to do, ie tells you if your lambda sensor is working ( flickers on part throttle to indicate you are in closed loop ) or goes to full green on WOT ( ie richer than sto ). Its a good indicator as long as you use it for these two purposes only. It does tell you if you are leaning out at high rpm when the gauge flickers off the green at WOT, so I think its pretty useful in a limited sort of way ( if you know what I mean )

Can't beat a proper wideband though.... 8)

 

[purplemonster]

well i have had an a/f gauge in my past 3 cars ,and i have used the same gauge
in my opinion they are a worth while fit ,and i have also tuned 2 cars using them,may not as good as a wide band ,but still dose a very good job ,they seem not to work so well in an R due to nissan very crap fueling and nothing else .

people put them in Rs and think they are crap and dont work properly,?
i fitted one ine my 2litre mini turbo and used it to tune the car and its quite accurate ,and u will get a steady reading if u can adjust the fueling yourself like i was able too


just my 2p worth

 

[GINGA]

At a guess the reason the afr gauge worked on your mini was becuase it was better suited to the lambda fitted, the off the shelf gauges that most people buy that connect to the standard R sensor just aren't suited to the lambda sensor fitted to the R and hence give inaccurate readings i'm not sure why though as most gauges are set up for a 1 volt lambda sensor which is what the R is supposed to have :?
Even with a gauge with its own dedicated lambda it still flicks between rich/lean on idle and cruise as its the ecu switching the fuelling between rich and lean in its closed loop function but is much more accurate than the normal gauges.
I at first had a lumenition 19 led gauge fitted to my car and according to that it was running realy rich as soon as the throttle was pushed like right off the scale :shock: but on fitting the greddy gauge with it own sensor it showed it was running dangerously lean (14:1) and whats more the later i found out that even the greddy one was out by 1.5 afr to rich which would have meant the other gauge was showing the fuelling to be well rich even though it was only running about 15.5:1 afr.

 

[AJ4]

Sounds like you had a bad run of things

I recently repaired one of the Autometer ones for a board member, so i know what is inside them and how they work. The autometer is a bog standard 0-1v bargraph, thats all it does. If it is reading wrong then its a fault of the lambda sensor, not the guage. I calibrated the guage when I fixed it and it was spot on.

You are right though - they are pretty useless for tuning purposes, all it does is tell you the two extremes lean / rich.

Maybe the standard lambda sensor is offset in some way, so that perfect 14.7:1 isn't 0.5v but 0.8v or something. Will have to investigate, might be of some use to someone ( just got to figure our a way of testing it now )

 

[AJ4]

Actually, that might make sense - there was a recent thread about the standard Pulsar sensor giving 1.5v max and not 1.0 volt as normal. That would mean that the AFR guage is pretty much useless :shock:

I put a new sensor in mine last year, straight from Nissan, but it has only ever reached 0.95v, so maybe I got the wrong one from Nissan, but the correct one for the guage to work properly ?? And I have been running really rich since then as well, which I put down to the fuel pump.... :shock: :shock: :shock:

 

[Olly]

I have the Autometer one and find it usefull, it only shows what the ECU see's but it does only work from 0 to 1 Volt i have seen 1.5 volts on my voltmeter when connected to signal wire on stock lambda so its just a guage for warning between rich and lean. But I'm gonna add a 0 to 1 volt Ford lambda sensor to work with my 5th injector driver 8) cos thats the set operating values.

Ross: Check your readings mate on a voltmeter then if you see 1.5 volts you will see what i mean.

Edd does you know what closed and open loop fueling is? :lol:

 

[AJ4]

Olly, as I mentioned in another thread, I data logged my lambda sensor / afm, tps etc over a period of a couple of weeks trying to fault find a misfire problem, and the lambda sensor never went above one volt. I was logging at a period of 1ms so I would have seen any spikes etc.

I'm guessing I have a 1.0v lambda sensor in there by mistake, I got a new one from Nissan but there is no guarantee that they gave me the correct one for that model, maybe I got one from a different model that uses a stock 1v.
From what I could see, it looked like the ECU supplied 1v to the sensor, and the sensor resistance dropped with increasing lambda, so its more like a 1-0v sytem and not 0-1v :? I've noticed on two seperate guages now that when the gauge is powered up but with no signal it shows full green, which means it is floating at 1v and gets pulled down by the sensor...

Doesn't explain why some people get 1.5v though, but it seems to be the norm :shock: I think I've got some serious investigation to do....