ok, so today, i was shooting the **** with some of my friends at the shop regarding their a/f meters. i explained that when at idle, everything that i have read says that the LED should bounce back from lean to rich. is this correct? i think it is, because everyother one that i have seen does it. MINE DOES NOT. it usually, whence properly warmed, stays around the upper end of the stoich end. [today] i was told that there was a good chance that my o2 sensor was bad, and that i should change it anyway. so.....being the proper fd maintainer that i like to be, i went and bought the UNIVERSAL bosch O2 sensor from advance auto. it was dufficult to install because it was bulkier and wanted to touch the framerail and i just used a prybar and torqued the engine over about a 1/2" and got it in there......well, aside from the fact that i think that the wire and connector lead off of the new sensor was a bit toooo short, i got it all connected.....but i am not sure that the best connection was made. i am going to retry in teh morning and put a different connector on it.......





with the new sensor in and when it properly warms up, it still does not bounce like the others that i have seen......





[SIZE=14]WTF???[SIZE=14] https://www.nopistons.com/forums/pub...O_DIR#>/11.gif am i running focked up because i am still the factory ecu, and am too cheap to buy an upgrade right now?????or is something else the matter.

at idle mine also does not bounce back and forth https://www.nopistons.com/forums/pub...IR#>/dunno.gif

Well, they're right, and they're not...



If your a/f is bouncing, that signals a change in exhaust oxygen levels...



Think about this very carefully, turbo cars shouldn't really see this. What kind of cars do they have?



Okay, mine does not bounce, I have the Apexi digital display in my turbo timer, it stays nice and steady. My motor is in perfect condition, it's never been healthier!

well, that is what i thought too, but the rob robinette site says that it should bounce and teeter inbetween the lean and rich ranges.....what was he doing differently....





louis

what's his site??



bouncing between lean and rich is quite drastic.. you saying it'll bounce between 12.5:1 and 16:1.



Maybe a little bounce between 14.5:1 and 14.8:1, at most. the fuel control should be very stable, unless you have something wrong. Maybe also with a wideband it would bounce, https://www.nopistons.com/forums/pub...IR#>/dunno.gif . Really, it should be pretty stable at a standard idle.

no, i mean at idle......i peg a pretty stoich mixture in 3rd &4th gears and really do not pull in 5th.....the led's *should* bounce at idle since it is in closed loop and runs a 14.7 at idle.....



rob's site, forwarding link

Hmm, my Power FC stayed constant voltage at idle. It bounced a little cruising. I take this to mean it is not in closed loop at idle, it is while cruising @120 km/h on the highway. @ 130 km/h it was constant again.

ok!



any more of you guys made observaitons on the A/F guage.....one not on the Pfc is preferable....



thanks...



louis

I think you gotta remember that the stock o2 is a narrow band o2, its use on the stock ecu is to keep it stoic in closed loop which is usually light part throttle and idle, mine seem to stay on the rich side as well during idle but it's not to say that the o2 is still not cycling, its probably cycling on the rich side, narrow o2 supposd to be 0.01-0.9v-lean to rich, a proper working o2 should cycle



anyone else think that those pos air/fuel gauge's are kinda useless (for tuning), I think the only good use it has is that you can tell if your running lean, not so good for tuning



I think for more accurate tuning and real a/f's you gotta go wide band, but I guess that's just in my opinion

I have an AutoMeter Ultralite A/F gauge on the stock O2 Sensor with ~60K on the odometer and once warmed up, the gauge reads steady at or near full rich at idle. It only seems to fluctuate at cruising speeds with light throttle. Hope this helps.