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Hi Ernest,
Not that familiar with the Microsquirt system. But,
If I am interpreting parts of your graph (your Air/Fuel Ratio), it looks to me
that yes, the Fuel dramatically increases right after start to around 10:1, but
then it drops off to around 22:1 - a very lean mixture as you pull the throttle
back.
My experience has been that at idle the air/fuel ratio
required is higher than cruise. Supposedly the ratio of accessories (water
pump, alternator, oil pump etc) are a higher proportion of the small amount
of power being produced at idle - therefore a higher air/fuel ratio is required
to get the most power out of the relative small amount of air going through
the engine at idle. As you know, you can have a 12.5:1
air/fuel ratio at any rpm/ manifold pressure - its just the absolute amount of
fuel at that ratio is much lower at idle than WOT.
. The MAP appears to correlate with the fuel ratio,
in that when the MAP is WOT (I presume that is around 46.4 Min (min pressure =
max vac?) then the airfuel ratio is at its highest (near 9:1). While that
is a bit rich in my opinion even for WOT (best power is around 12.5:1), I don't
find it unreasonable for starting out your tuning process.
The A/F ratio is jumping around
but it appears to be in sync with your MAP also jumping around - so no surprise
to me since the two are sort of wedded.
So the 10:1 ratio is either a large increase in fuel at
that point - OR a considerable reduction in air density at that point.
Either will can give you the 10:1 ratio.
Get your oil leak fixed and give us some more
data
Ed
Sent: Monday, May 16, 2011 11:21 PM
Subject: [FlyRotary] Reliably starting
I adjusted the VE tables, and my engine started and
ran MUCH smoother than yesterday. This graph shows the result of several
starts this evening. It is just a couple of blades and the engine is off
to the races. Problem is that the AFR drops to as low as 10, then jumps
all over the place. Looking at the tuning parameters, my cranking
pulsewidth for the injectors is WAY to high, and then I have no after start
enrichment.
I would update those and go run some more, but I've developed
an oil leak on the propeller side of my PSRU, and I think my blower has come
apart. I've got to tear down the front of the engine and figure out what's
going on. I might also have a leak between the bed-type mount plate and
engine. I'm not even wanting to think about that one right
now.
...building and airplane => put it together. Pull it
apart. Put it together. Pull it apart......
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