It runs now! (pulls liike a beast too)

[David Cooley]

At 09:21 AM 6/21/99 -0500, you wrote:
>Thanks, now I've heard these numbers from two sources so I feel a little 
>more confident in them :^)
>The ECM can use a standard o2 sensor or a wideband one; we currently have it 
>setup for the stock o2 sensor.  One thing struck me, though -- we're using 
>the 130,000 mile 12 year old O2 sensor still... maybe it would be a good 
>idea to get a stock replacement for it, at the very least.  The wideband 
>sensors are a little pricey still.
>As for the swinging back/forth, isn't that a function of the sensor itself 
>rather than the program?  I would think that once you approach the ideal a/f 
>ratio I should be able to see the voltages swing, no matter the ECM...

Actually, it's a function of the ECM from what I was told... The O2 sensor
function is a curve like so:

             ----------------
            /
           /
          /
         /
---------

There is a bit more curve on the upper and lower ends, but not much...
Basically the voltage change thru stoich is a sharp change (basically the
middle vertical slope).  For the output voltage to swing, the mixture needs
to cycle rich/lean (referenced to stoich) which is what stock ecm's do...
If they held the mixture constant, and tried to get a constant voltage out
of the O2, they would set a trouble code, as the voltage swings are what
flag the software as being a good sensor.
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David Cooley N5XMT Internet: N5XMT at bellsouth.net 
Packet: N5XMT at KQ4LO.#INT.NC.USA.NA T.A.P.R. Member #7068 
We are Borg... Prepare to be assimilated! 
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