do A/F gauges have any point at all?

[Wikdboost]

i have a stock 02 sensor in my 95 eclipse and it looks like my car has been heavily modded before i bought it. my A/F gauge reads FULL green when i floor it, wich means fuel rich. does this mean anything at all, some people have told me the A/F gauge means absolutly nothing and should be thrown away? could this mean i have a rewired fuel pump or a bigger one? or even bigger injectors? or is the A/F gauge a piece? its a brand new 02 sensor and it gives a full rich reading when it is warmed up.

??

 

[allwheelTSI]

they serve a purpose,they give you a baseline estimate,but you can't rely solely on it to know your mixture.

 

[Defiant]

They fill a big hole in the gauge pod, which prevents hornets from nesting in there.

 

[alIan]

they can look pretty sometimes...

 

[Agent Ezzard]

I have brought this up in the DSM1gina2g yahoo group because most "hardcore" guys say you don't need it. I think they serve more of a diagnostic purpose especially for 1g and 2g's with a 6 bolt or 2g's with the 1G style CAS. After becoming accustomed to what the gauge should read, you can quickly spot when something is not right. Whether it's a vacuum/boost leak, jacked up base timing, or any other situation that can severly affect AF ratios.

 

[44pirate]

Alone it tells you if your O2 sensor is working order. In conjuction with a logger you can visually corilate a # to the position of the lights.

 

[Idiot Stick]

Originally posted by allwheelTSI
they serve a purpose,they give you a baseline estimate,but you can't rely solely on it to know your mixture.

, that's helarious. and yes it does let ya know when sumpin is not right when your used to what it should read.

 

[DSMJim]

The problem is it will light up the same light for anything between .88 and .94v from the O2 sensor. There is a BIG difference between .88v and .94v when you tuning. So no it will not really tell you when something is not right because that's a pretty big damn range.

Here is the million dollar question. Can anybody tell me the difference between .88v and .94v at WOT with a 2G turbo charged DSM?

Hint: It invloves melted pistons...

 

[pickens]

I use it as a boost leak check, and also a quick dianostic tool. If my car runs full rich on the A/F gauge then I know I have a new boost leak. If my cel comes on when I 'm away, I usually watch the a/f gauge to see if it does something funny and that'll tell 9 times out of 10 that a vacumm hose must've popped off. So, it has some use I guess.

 

[wret]

Using mine I was able to determine that the UICP had blown off the throttle body elbow the other day. To be fair, there were a couple other clues.

 

[Defiant]

Originally posted by DSMJim

Hint: It invloves melted pistons...

Yeah, but DAMN that molten aluminum puts out POWER ....for almost half a second....

 

[Enigma_Man]

(very long, I've typed it before, but this is how O2 sensors work again, and this should really be in the n00b section, and you should really have read this already)

The autometer blinkey-light disco-ball ones aren't really good for much, other than if there is something _terribly_ wrong, like an IC pipe has popped, or your engine has blown up.

The reason is this: On the autometer gauges, there's maybe 25 or so LEDs of indeterminate value... You don't know what any particular LED has for a value (the LED is the little light thing). Also, with a stock O2 sensor, essentially all it reads is "rich" or "lean" in respect to a 14.7 air-fuel ratio (richer than 14.7 gives about a 1 volt output. leaner than that gives about a 0 volt output). It switches very fast.

When our cars are just cruising around at low-throttle, you'll notice it sweep up and down, up and down about 2x a second (or so). This is the sign of a properly working O2 sensor. The car uses this to tune itself when driving mildly. However, when you step on it, the car ignores the O2 sensor, because it is not good at saying anything other than "rich" or "lean", it doesn't tell _how_ rich or _how_ lean. The car just hopes that the MAF sensor is working correctly, and aims for something like a 12:1 calculated air/fuel ratio.

Now, you can buy a digital display type O2 gauge, which will show you the actual voltage level, with a couple decimal places of accuracy. What you can do with this is just use it to verify that you aren't running _too_ lean, because the O2 sensors can be used somewhat (and poorly) to get a rough estimate of rich/lean. If you get a voltage of around .9 or so, that's usually fairly rich, while .8 is maybe a little risky on the lean side. These numbers change depending on the temperature of the O2 sensor, how old the sensor is, the time of day, what color pants you're wearing, and many other variables.

So... Autometer LED blinky thing = good for making sure that your O2 sensor is working at all, not much else.

Digital O2 sensor = good for letting you know if there is danger, not to be relied on completely for tuning.

Wideband O2 sensor = what you wish you could afford, because it actually reports _actual_ air/fuel ratio.

That's the story.

 

[dsmturboawd]

air fuel gauge is the same thing as fuzzy dice hanging from the mirror.

-annoying
-doesnt do dick
-lets girls say "oh, thats cute"

thats it dude.

search yahoo for a site called "DIY Wideband"

 

[Groomz]

Originally posted by DSMJim
The problem is it will light up the same light for anything between .88 and .94v from the O2 sensor. There is a BIG difference between .88v and .94v when you tuning. So no it will not really tell you when something is not right because that's a pretty big damn range.

Here is the million dollar question. Can anybody tell me the difference between .88v and .94v at WOT with a 2G turbo charged DSM?

Hint: It invloves melted pistons...

One's a pinch too lean. But it makes delicious piston soup. I hear a tasty blend of 10W-20 makes it really kick.

 

[ericismyname]

Originally posted by dsmturboawd
air fuel gauge is the same thing as fuzzy dice hanging from the mirror.

-annoying
-doesnt do dick
-lets girls say "oh, thats cute"

thats it dude.

search yahoo for a site called "DIY Wideband"

Lmao

 

[DSMJim]

Nobody here know about the Tech Edge Wide Band 02?

Check out this link..

http://wbo2.com/lsu/default.htm

It uses a Bosch LSU 5wire sensor instead of the Honda L1H1 sensor. They are proven just as accurate.

I bought the whole unit it cost me about $550 canadian (around $450 u.s.) and the sensor was $25 (vs. $100 for the L1H1 sensor)

I have used it on several occations and it works really well. I cleaned my car up at the track and picked up 2mph by the 1/8th mile but didn't get a clean enough pass before the end of the day to beat my best 1/4 mile. I did top my fastest 1/8th though just with tuning using the Tech Edge WB02.

It's a hell of a lot cheaper than FJO or any other brand out there. I bought it never having heard of anybody using one before or any reviews and I have to say it's a really nice piece. We have an FJO wideband unit at the shop and it's no different. Good think about this one is it will hook upto a palm and you can input RPM with it and log it as you drive. Then go back and check and see exactly what RPM that your rich or lean in then make the required changes.

It's a pretty slick unit...

 

[jdmawd]

i rock the tech edge also there is a huge thread about it here