[Diy_efi] WBO2 and AFR

[Adam Wade]

--- Tim Marsteiner <tmarstei at yahoo.com> wrote:

> As you retard ignition the AFR reading gets leaner!
> If you tune with retarded ignition you will end up
> being rich. This is not insignificant!

*ding*  Give the man a cigar.

An O2 sensor, WB or otherwise, gives partial pressure
of O2 in the exhaust.  Retarding the ignition timing
means less complete combustion (when retarded notably
from MBT), which means more HC *and* more O2 in the
exhaust.  If you're just measuring partial pressure of
O2, then your O2 sensor will "tell" you you just got
leaner, when this is not, in fact, the case.

The key to using data usefully is knowing what they
will (and will not!) tell you.

| 82 Honda CX500 Turbo (Cassandra)  90 Kwak Zephyr 550 (Daphne) |
| "It was like an emergency ward after a great catastrophe; it  |
|   didn't matter what race or class the victims belonged to.   |
|  They were all given the same miracle drug, which was coffee. |
|   The catastrophe in this case, of course, was that the sun   |
|     had come up again."                    -Kurt Vonnegut     |
| M/C Fuel Inj. Hndbk. @ Amazon.com -  http://tinyurl.com/6o3ze |

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