tuning carb with A/F ratio gauge

[maytag]

Hey all!

Some of y'all may remember the difficulty I had in getting my car to pass the emissions test. Eventually, I discovered that a previous owner had jacked-up the jetting. I got it to pass beautifully, and it ran well too... but I knew I had to do more. Ya see, I'm at 4000' in elevation here... and I have no reason to think that what works in Vegas (or California, or wherever) will work well here.

So Thursday evening I installed a Lambda sensor in the exhaust manifold and an Air / Fuel gauge in the dash (as it's temporary, I just stuck it where the clock would otherwise be). After driving it for a day, and noticing the patterns of lean / rich, I re-jetted last night, and today, the thing is AWESOME! I may still go one size larger on the primary fuel jet.... but I might wait still. Peirce manifolds sent me the wrong style primary idle jets, and mine is so worn, I need to get it replaced before I go any further.

But:
chalk this one up as a success!

I'll post pics if anyone cares. But I was just excited to share the success!

[racydave]

I have always wondered what could be done monitoring a O2 sensor. Im not familiar with the lambda as mine is carbd. I do have a place in the header for the sensor.

[maytag]

my car is carb'd as well. The Lambda is just an O2 sensor. I had to weld-in a bung for the sensor, so if you've already got that, the hard stuff is done!

Really, it was quite eye-opening, and helped me do a little better than just a seat-of-the-pants trial-n-error re-jet would've done for me.

[racydave]

A o2 would use a voltmeter for a gauge average should be .5 volt? Hows yours work???

[maytag]

A o2 would use a voltmeter for a gauge average should be .5 volt? Hows yours work???

just like that.... but AutoMeter (and many others) build a gauge that measures the voltage and translates that to either a needle-swing or, as mine is: an LED array.

So basically, I've got a gauge with 3 red LED's, 3 Yellow and 3 Green. Red is lean (1 red is lean-ish, where 3 reds is very lean), Green is fich (progressively richer with more LED's) and yellow is good, with one yellow in the middle being at or near Stoichiometric.

The benefit of the gauge, as opposed to reading a voltmeter is the ease of reading it quickly, while driving. It mounts in the same hole as the clock, so no modifications to speak of, which is important, since it's temporary.

[htchevyii]

I have a a/f meter that uses the stock narrow band o2 sensor, neat to look at, but not very accurate. You have to pony up the dough for a wideband set up to get something usable, (I have yet to install my Innovate Motorsports set up).

[maytag]

I have a a/f meter that uses the stock narrow band o2 sensor, neat to look at, but not very accurate. You have to pony up the dough for a wideband set up to get something usable, (I have yet to install my Innovate Motorsports set up).

well, it should be accurate, if it's working correctly. But I absolutely agree with you that the usability of a wide-band setup is greater, because of the range that you can see. in other words: I'd be hard-pressed to tell you if I'm at 14.7:1. "somewhere between 14 & 15" might be the best I can do.

But for now, I'll take it!

[racydave]

Links????