Mailing List flyrotary@lancaironline.net Message #5117
From: Tommy James <twjames@statesville.net>
Subject: RE: [FlyRotary] Re: alcohol in mogas...test and avail
Date: Mon, 5 Jan 2004 18:14:28 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
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 {:>).

    I suspect you are correct that it is fuel system related.  If it were
ignition, the odds are it would quit completely rather than just run rough.
Did you by any chance notice your  RPM,  EGT, fuel pressure or air/fuel
mixture LEDS when this was happening.  I know - tough to divert you
attention to details when this happens in the air, but you might pay some
attention to what those   instruments are telling you when if happens on the
ground.  Also, did you ever have any luck with the simple fuel flow meter?
**Ed, I was so distracted, and the episode was so, brief, that I didn't
notice any instrument readings.  The fuel flow meter is installed, but it
reads ".12 or .14" at 4800rpm, so I'm not what I'm seeing.

I would suspect that perhaps too little fuel might be the cause,  my
experience has been that once the engine is running above 4000 rpm, you can
pump almost any amount of fuel into them and they will continue to run
(almost impossible to flood to the point of quitting once at those rpms) as
any unburned fuel is apparently blown out into the exhaust headers.  I have
notice no missing or quitting under too much fuel although my EGT will drop
several hundred degrees when too much fuel is flowing.
**I don't think it is a problem with too much fuel, but I did have a take
off where power dropped because of too lean a mixture at WOT.  When the
engine spooled up, the computer leaned the engine and rpm dropped.  My
programming you know.

However, too little fuel and the engine will start to run rough at some
point and may quit.  Just a thought.  Too little fuel could be due to
water contamination--** I think so, will drain and use fresh fuel
restricted fuel filter--**I'll replace filter
low fuel pressure, --** Don't think so.
malfunctioning injector --** Don't think so,  but.....
fuel MAP not set appropriately,*** High probabilty if mixture meter is
reading too high.  For most power settings, I set to for 6-7 bars
etc.  ** this is the area that really gets to me, I can't ever get them
all..:-)

It does not sound like the spark plug SAG, however, depending on how many
hours your have on your plugs, you might try a new set of plugs  just to see
if they made any difference.
**The plugs are okay.

    If no water is visible then here is another suggestion - check any fuel
filters.  I am unfamiliar with what your fuel tanks are make of or if you
seal them with anything.
**Metal tanks, no sealer.   I am about to order a new filter element.  I
have the same Mallory high flow that you use. (I think)

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<><





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