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Re: [FlyRotary] Re: ECU oxygen sensor
I certainly would not draw that conclusion,
Bulent. I have found theLED A/F indictors such a good indication of
what my engine is doing that I would hesitate to fly without it now. If
the engine starts to stumble you immediately know whether it because its too
much or too little fuel - sort of nice to know, trust me. {:>)
Ed Anderson
----- Original Message -----
Sent: Monday, December 06, 2004 2:04
PM
Subject: [FlyRotary] Re: ECU oxygen
sensor
On 12/6/04
12:02 PM, "Russell Duffy" <13brv3@bellsouth.net>
wrote:
I have been
looking at various ECUs trying to understand how they
work.
Fortunately, I was on the phone, and Ed just
saved me a lot of typing :-) One additional note, ECU's can run
in open loop, or closed loop modes. Tracy's EC-2 is open loop all the
time. Basically, in open loop, you supply a pre-designated amount of
fuel from a look-up table, and you trust that it's what you wanted.
When we tune the EC-2, we're making this look-up table. In
closed loop mode, you start with the look up table number, then check the O2
sensor to see how close you came. The ECU can add or remove fuel as
needed to hit a target O2 number.
Cars use closed
loop whenever they can, or emissions and fuel efficiency, but they also run
in open loop mode under certain conditions. For example, you're car
will run in open loop mode when you first start it, because there's no valid
O2 sensor reading until it warms up. Multi-wire heated O2 sensors have
shortened this time considerably over the years. I think most
cars also run in open loop mode during full throttle
operation.
Rusty
Sooo, I installed an 02 sensor
for nothing?
Bulent
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