Message-ID: <005801c3d456$6507ecc0$1702a8c0@WorkGroup>
From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-2918447@logan.com>
Subject: Re: [FlyRotary] Re: alcohol in mogas...test and avail
Date: Tue, 6 Jan 2004 08:10:02 -0500
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 Subject: [FlyRotary] Re: alcohol in mogas...test and avail


> Hi Ed,   Read responses below>
>
>     Glad to hear the engine didn't stay stopped - raises the adrenaline
> levels even when it misses, and the flow of time is definitely altered
{:>).
>
>     .... SNIP


>
> Hope you get it fixed quickly.  I just hate intermittent problems - well,
> intermittently quitting engines while in the air are better than one that
> stays stopped {:>)
> ***Ditto,   Thanks for the help!
> Tommy<><


Tommy, Looks like you are taking care of all the things I could think of.  I
agree that the likely cause is overly lean.  I took off one day when I had
the old HALTECH EFI system after installing my new (2nd) intake manifold.  I
could only adjust the MAP to 5000 RPM on the ground, so extrapolated for the
above 5000 RPM range planning on refining it in the air.  Well, at 80 MPH
5300 rpm and 20 ft off the ground the engine began surging from around 3000
rpm to 5300 rpm.  Really got my attention.  Make the decision to abort the
take off, touched back down 300 ft from the end of the runway and due to
great brakes, gripping tires and dragging my shoes managed to get it slowed
down to just end up 12 ft off the end of the runway in the grass.  The
HALTECH later failed so switched to Tracy's EC2.

The culprit was too lean a fuel map. When the rpm increased it ran into the
too lean region which caused the engine to loose power, rpm to drop until it
got back into a good mixture region of the map, where the engine would catch
again and start back up the rpm range until hitting the lean region and then
would repeat.

You say the fuel mixture meter reads 0.12 to .14? at 4800?  It should be
reading somewhere between 8-10 GPH.  I suspect that you may have the signal
wire on the wrong side of the injectors and it is only reading the pulse
voltage drop across some wire resistance (like 0.12-0.14 volts) instead of
across the injector.  When you get the time and inclination, try switching
the signal wire to the other side of the injector wiring.

Or when you get the bird to NC, let me know and I can take a look at it.

Ed Anderson