O2 / Lambda Sensor Data

Will Reeve will at oxfordcryosystems.co.uk
Thu Apr 26 14:11:59 GMT 2001


>> I come from an applied physics upbringing and I know 2 cars is not
ideal,
>> but it's better than 1!
>
>I fail to see where that is an excuse for giving out poor info..
>

Poor info? I was reporting my experimental results. I outlined the
experiment, and reported the results, these results are repeatable, and
have been independently verified with a completely different set of
components. I don't (and didn't) state that the readings are absolute,
however with a accurate calibrated mixture meter stuck into the exhaust
I think the unit could be calibrate to report more precise ratios. From
my experience a lambda sensor and meter combination CAN and DOES measure
an increase or decrease in WOT injector duration on these vehicles.

>> As long as you keep the sensor roughly at the same
>> temperature for DIY use I think it's fine, it may not be absolute but
it
can
>> measure the presence of more of less fuel, even off stoichiometric. I
hope
>> to get a thermocouple in there soon to monitor the temperature.
>
>Might read further and see that backpressure can also play a role.
>Also, not all sensors switch over at .5v.

Obviously need to get one whose response matches the curve programmed
into the meter, which is the Bosch zirconium dioxide example.

>> I wouldn't know how to read the plugs accurately and the only trouble
is
you
>> can't read the plugs while they are still in the engine :-) One
advantage
I
>> didn't mention is that the WOT map curve isn't perfectly flat. I
guess it
>> takes into account the volume efficiency of the engine. The standard
curve
>> shape gave a wobbly mixture across the range(read from the mixture
meter),
>> we re-shaped the curve to give a constant mixture reading throughout
the
rev
>> range.
>>
>> I'll be the first to admit I don't know the ins and outs of engine
tuning.
>>
>>And you want to give advise?.

Reading back through my posts I don't think I was advising at all, just
reporting what I did, and interpreted my results. People can do with
them what they want. I thought I might be helping the original poster a
bit, that's all.

>> I'm just a evening hobbyist, but the car feels better now, and
hopefully
>> will give a few more ponies at the rolling road (at 60quid a throw I
can't
>> afford to tune it on the rolling road itself, and besides it fun to
have a
>> go yourself)
>
>And remember, Buttometer readings are meaningless.
>

P.S. Can we take this argument to personal email? I don't think the list
is the place for it :-)

Will
will at reeve.org.uk
----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org




More information about the Diy_efi mailing list