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1. 05:47 AM - Re: Help me solve engine power loss (Steve Thomas)
2. 10:24 AM - Re: Help me solve engine power loss (FLYaDIVE)
3. 09:20 PM - Re: Engine power loss (DEAN PSIROPOULOS)
Message 1
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Subject: | Re: Help me solve engine power loss |
Have you checked the integrity of your engine electrical ground?
Steve Thomas
________________________________________________________________________
On Aug 3, 2012, at 6:55 PM, Speedy11@aol.com wrote:
>
> Engine gurus,
> I have a problem with my engine that has me stumped. Maybe someone has seen
this situation before or has an idea for resolution.
> I have a Barrett IO-390 (essentially same as IO-360) that began missing and losing
power in June. I tracked down several "problems" which the solution to
I thought would solve the power loss. I found one spark plug that seemed to be
a problem. Replaced all plugs and tested them before installation. Problem
still there. Checked resistance in harness. All good. Replaced harness anyway.
Problem still there. Sent P Mags back to factory for overhaul. Essentially
have new P Mags now. Problem still there. Cleaned injectors and flow
tested. Flows all equal. Cleaned fuel filter - nothing there. There is no air
filter when I run ram air, so nothing to inhibit air flow. I checked the sniffle
valve but no leak there.
> On takeoff roll there seems to be slightly less power, but the power loss is
more noticeable (approx 20% loss) once airborne. At pattern altitude with reduced
power the engine runs ok. But as I add throttle (high RPM on prop) the engine
loses power as if it is loading up. The EGTs and CHTs are normal. The
RPM and MP are normal.
> So, there you go. Any ideas?
> Stan Sutterfield
> RV-8A. Port Orange, FL
>
>
>
>
>
>
>
Message 2
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Subject: | Re: Help me solve engine power loss |
Stan:
Some ideas I had:
- How did you clean the injectors? A standard way is to soak them in
Hoppies #9 Gun Solvent. The flow could be all equal - But they could be
all slightly restricted.
- Does the fuel lines from the spider contact any part of the engine?
HEAT could be causing a vapor bubble.
- Since you have a CS prop, do you think or feel the loading ONLY when
increasing the RPM? This could be a SLOW reacting Governor and that would
cause loading.
- Can you monitor your ALL your EGT 's at the same time and see if a
cylinder drops in temperature at the same time loss of power occurs?
- The spark plug that was a problem: Was it indicating Oil or Carbon?
Keep an eye on that plug and see if the problem begins again. It could
indicate a sticky Exhaust Valve. So, replacing the plug will not fix the
valve.
- Have you done the Valve Wobble test (SB-388)?
- OK, with this one I am reaching a bit: I have read about someone that
"Improved" the intake air flow to the engine. And in doing so, the forced
air was so great that it disturbed the airflow through the Carb. - I know
you do not have a Carb, but how does it fly without the Ram Air?
- Have you inspected the ducting - I'm guessing SCAT Tube. Could that
have an obstruction or could it be collapsing?
That's all for now...
Barry
======================
On Fri, Aug 3, 2012 at 9:55 PM, <speedy11@aol.com> wrote:
>
> Engine gurus,
> I have a problem with my engine that has me stumped. Maybe someone has
> seen this situation before or has an idea for resolution.
> I have a Barrett IO-390 (essentially same as IO-360) that began missing
> and losing power in June. I tracked down several "problems" which the
> solution to I thought would solve the power loss. I found one spark plug
> that seemed to be a problem. Replaced all plugs and tested them before
> installation. Problem still there. Checked resistance in harness. All
> good. Replaced harness anyway. Problem still there. Sent P Mags back to
> factory for overhaul. Essentially have new P Mags now. Problem still
> there. Cleaned injectors and flow tested. Flows all equal. Cleaned fuel
> filter - nothing there. There is no air filter when I run ram air, so
> nothing to inhibit air flow. I checked the sniffle valve but no leak there.
> On takeoff roll there seems to be slightly less power, but the power loss
> is more noticeable (approx 20% loss) once airborne. At pattern altitude
> with reduced power the engine runs ok. But as I add throttle (high RPM on
> prop) the engine loses power as if it is loading up. The EGTs and CHTs are
> normal. The RPM and MP are normal.
> So, there you go. Any ideas?
> Stan Sutterfield
> RV-8A. Port Orange, FL
>
>
Message 3
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Subject: | RE: Engine power loss |
I had a problem with a bad idle on my AFP injected parallel valve 0-360
Stan. After 5 months of trouble shooting I discovered that the flow divider
(on top of the engine) was sticking. How I figured that out was to tee in a
mechanical pressure gauge between the servo and the flow divider (not at
fuel pump outlet, you won't get accurate readings there). You'll need one
calibrated with a 0-10 PSI range. I ran a hose up to the canopy from the tee
and connected it to the gauge there so I could see the reading from the
cockpit. Then I started the engine and watched the gauge while I was
advancing the throttle. The engine stumbled and the pressure reading went a
couple PSI above where it should have been before dropping back and acting
normally (ie. going up and down with throttle movement). After consulting
with Don Rivera at AFP the conclusion was a sticky flow divider so I
returned it to him for repair. The engine ran like a top after it was fixed.
Another friend with a Bendix system found a small piece of black tape
plugging up one of the fuel ports in his flow divider but that was during
first run when one EGT showed a cold cylinder (so much for the integrity of
FI rebuilders). After that was fixed it still ran a bit rough and when he
did the flow matching test (with the 4 cups under the injectors) he found
one somewhat constricted. So he soaked that injector in Hoppes gun cleaner
and viola, engine runs great. Troubleshooting the fuel system can be very
frustrating. By the time I finally figured out the flow divider problem I
was so disgusted that I had started to look for a Marvel carb. And I'm a
pretty patient guy.
Dean Psiropoulos
RV-6A N197DM
FL to Indy 2012 without a hiccup
__________________________ Original Message _____________________________
Subject: Engines-List: Help me solve engine power loss
From: speedy11@aol.com
Engine gurus,
... On takeoff roll there seems to be slightly less power, but the power
loss is more noticeable (approx 20% loss) once airborne. At pattern
altitude with reduced power the engine runs ok. But as I add throttle
(high RPM on prop) the engine loses power as if it is loading up. The
EGTs and CHTs are normal. The RPM and MP are normal.
Stan Sutterfield
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