A/F Gauge
A/F Gauge
I just installed an air fuel ratio gauge(Autometer Ultra-lite)... My queston is, is it suppose to jump around when it's on? during normal driving, mine will start to spaz. Unless I gun it will it stay steady. Anyone that can shine some light on this mater would be great.
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Structure240sx
- Posts: 5615
- Joined: Sun Oct 06, 2002 5:04 pm
AFG
got one on my 97.but it stay steady all the time unless you get up on it. i have mine wirerd to the first o2s. when you first start your car it should read rich and slowley lean out.your o2s may need to be replaced or it may be stop up.
well it is supposed to jump between the two. The signal the o2 sensor sends to the ecu is either 0 = lean or 1 rich. When it's bouncing between the two, you're good as the o2 sensor's voltage must be a 0 or 1 that the ecu reads. So if you're between the two values, the ecu will do jumps between rich and lean, constantly trying to adjust it and you will see it jump between the two values. Just like Hurrikane said though, when you start up your car, it will run rich as it's trying to warm up. When it's warm and running however, it will start to bounce if properly adjusted. If you're using a wideband o2 sensor it is safe to use the S-AFC to adjust your fuel maps so you don't run rich or lean.
He means it's no good for tuning and he is completely correct. It may give you SOME warning in the event of an uber-rich or uber-lean situation, but for the most part it's for worthless ricers who want a bling-blinging gauge. And your replies make NO sense in proper English Hurrikane. Seriously. Take a class or something, geez. How in the name of god would someone "block off half the fuel". I swear, the fact that these people live is an insult to humanity........
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Structure240sx
- Posts: 5615
- Joined: Sun Oct 06, 2002 5:04 pm
stock o2 sensors aren't accurate enough, you'll need the wideband to get proper readings. They are however, pretty expensive and don't last long although they can give you the intermediate values with better precision enabling you to do your tune. Also be weary of EGT's as well. It's cool to have also, but you won't get proper readings unless you've tapped into the right spot on the exhaust manifold. If it's too far from the cylinder openings, you'll get a cold reading, too close to the cylinders, and you'll get a too high a reading. You want the egt sensor to be near the tip of the small flame that will shoot out your head (yes all 4 of them and equidistant from the temp sensor) as that will give you the most accurate reading for the EGT. The easiest is probably to go to a dyno and then get your maps tuned from there as they should be able to measure loss from lean/rich mixes from what the wheels are telling them than arbitrarily placed sensors in exhaust manifolds that weren't originally built to support such monitoring.
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Onizuka
- Posts: 8450
- Joined: Wed Nov 06, 2002 5:24 pm
- Car: 91 Nissan S13 coupe SR20DET
89 Nissan S14 hatch SR20DE
if you dont have a wideband O2 sensor it wont be very acurate, this is the same thing i have been hearing since I joined these forums a while ago. A knock sensor will give you much more pertinant information than that Air/fuel ratio gauge without the wideband sensor (i belive the new SAFC II has a knock sensor).
a/f
and cutting the brown and white wire and unplugging 4 and 5 gear sensor does not remove the speed limeter on 97-98 . and a g-tac doesnt work.thay why my time are .05-08 ten sec slower than the track timer and speed are 1-2 mph slower than track speed. and did i tell you that texas smogs now and that my afg reads just a tenth over a 40,000 dollar smog unit. time to bone up.
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240Kuminachu
- Posts: 286
- Joined: Sun Sep 01, 2002 4:54 am
afg
just look at the door plate.looks like i put in the wrong numbers. so is it 1925 or 1880. keep in mnd that you have to add in your weight and the weight of the gas in the tank.(8.5lb per gal) and all the rest of the add on you have done.i thougt that 4200 was a bit on the havey side.
Yep, that's definitely the wrong number. The number on the side is the GROSS weight, with 4 adult passengers. It's not 1925 or 1880 pounds. Just go get it weighed at a recycling center or something, it only cost me $5. Mine weighed 2940 with me (160 pounds) and 1/4 tank of gas/my old, heavy wheels. I thought gas was 6 pounds a gallon, not 8.5. Anyway, depending on if you have an s13/s14, I'd think yours would be around ~2950 or so. (Mine was pretty heavy bc the turbocharger added quite a bit of weight, as did my solid sway bars, strut tower braces, heavy wheels, etc).
afg
that sound better. i change the weight to 2300 lb and did 4 runs this moring.but i dont thing its right. i might go to the track tonight and do some runs on a go strip.in front of my place thair are a lot of pot holes and it throws the gtach off. low numbers the best was 120 hp. i have race 4.6 mustang gt and stayed on there but all the way upto 125mph.i dont think a car with 120 hp can do that. at lest i dont think so.