Mooney Engine Problems in Flight

This is a bit long winded but I'm looking for qualified opinions as to what
might have happed to an almost total loss of power while in cruise flight in
my Mooney M20F. Here is the story of what happened:

I was flying from Turlock (south of Modesto) to Petaluma (north of San
Francisco) on a Saturday. Weather was strange with a thick mist and fog layer
from about 500 feet to 2000 feet. I was VFR on top and there were no holes
anywhere through the fog/clouds/mist.

Prior to the flight, I sumped the wings with no indication of any water. I
did a normal run up and there were no issues at all. I was running on the
left tank which is what I had run on for the last 1/2 of the flight the night
before. Left tank had about 20 gallons right tank about 30. Take off was no
issue and full power was available with a good sounding engine. I found a
hole in the clouds and climbed to 4,500 on a heading direct to Petaluma.
About eight minutes into the flight (from take off), suddenly but not sudden
like a switch or electrical problem I would guess power output dropped to
around 30% with a decent engine vibration. It felt and acted as if two
sparkplug wires were simultaneously pulled from the plugs. I noticed the EGT
that I had leaned to 1320 F was now down to below 1000 F. I checked the mags
and there was no difference in operation between both, 1 or 2. I pushed the
throttle in full with no effect. I switched tanks to the right wing with no
effect. I turned on the boost pump with no effect. I opened the power boost
which bypasses the air filter which resulted in a tiny bit of improvement
maybe getting me up to 35% power. I moved the mixture in full rich and it
smoothed out considerably and I would guess power output moved up to say 45%.
My speed leveled off at around 124 knots from the 151 it was just prior. I
was able to hold 4,500 feet. EGT rose only about to 1100 F. I contacted
NorCal and advised them of my situation. They were great and offered vectors
to Modesto that I was right on top of according to the GPS. I advised them
that it was totally socked in fog that spread about 20 miles in all
directions. After about 30 seconds later I slowly moved the mixture out and
it began running extremely rough with no increase in EGT so I pushed it back
in scared that I would make it worse and loose my 45% power output. NorCal
asked what I wanted to do and as airspeed was being held, it was producing
about 45% power and I was holding altitude I told them I would forge ahead. I
felt this was less risky than dropping through the fog layer into 3 miles of
mist visibility with engine problems trying to find a runway with towers up
around 500 feet in the area. Time is strange and I'm guessing after about 5
minutes of this, I felt the plane pull forward like there was a significant
power increase and I noticed the EGT move up to 1190 F. I leaned it a little
and EGT went up to 1200 F max and quickly began to run rough so I slid it back
in to full rich. After about 3 more minutes I would say the power seemed to
up around 60% and I tried leaning again. This time it leaned like always
rising to a maximum of about 1410 F before running rough so I backed off to
run around 1310 F - normal operation. The whole event from the start of
something being wrong to full power being restored was I would say around 10
minutes. Maybe a little less. From that point on it was like nothing was
wrong. Remaining 30 minutes of the flight went without a hitch and the engine
responded just like it should and always has. I can only think that there was
some water stuck somewhere in the wing behind one of the baffles and the
engine just had to work through it. I can't think of anything else that could
have caused this behavior.

The following day I went out and did 10 sumps of each tank and the center
sump. None showed any sign of water. If it was a bad mag I would have
expected to loose the engine completely when I went to mag 1 or mag 2 but I
didn't. Only thing I can come up with is either water in the tank or an
obstruction in the line.

The engine problem would not have been so critical if I wasn't VFR on top.
Without an engine and VFR on top you have very little options.

Thanks for your opinions and advise. Please post any responses here.

Mooney M20F

PS. Other info is that fuel consumption was normal and I'm at just now at 6
qts of oil remaining after 16.5 hours since last oil change. So that works
out to be about 11.8 hours per qt. No other indications of problems. Except
of course the oil and gas dripping out of the plenum drain after stopping the
engine. Engine has about 80 hours since LMOH and has worked perfectly.

"Paul Smedshammer" wrote

This is a bit long winded but I'm looking for qualified opinions as to
what
might have happed to an almost total loss of power while in cruise flight
in
my Mooney M20F.

Giant snip

It sounds almost like conditions were perfect for induction ice, but is that
possible with this type of injection? Is there any provision for heat, or
just unheated alternate air?

This, from a definite unqualified person. Me. g
--
Jim in NC

VFR on top, not good if you and the plane are not capable of IFR flight.
Did the forcast call for any broken or scattered conditions along your route
of flight, if so where?? Water in the fuel system can lead to freezing in
the fuel line as you gain altitude. The weather report would give you the
freezing level. This can of course block and/or restict the fuel flow.
But, second guessing the problem is not too smart, I strongly suggest you
have a shop check it out, maybe a fuel pump was sucking air from a loose
fitting, etc. Have it checked out, and watch out for Mt. Diablo. Just
remember, always have options:
Clyde

"Paul Smedshammer" wrote in message
news
This is a bit long winded but I'm looking for qualified opinions as to
what
might have happed to an almost total loss of power while in cruise flight
in
my Mooney M20F. Here is the story of what happened:

I was flying from Turlock (south of Modesto) to Petaluma (north of San
Francisco) on a Saturday. Weather was strange with a thick mist and fog
layer
from about 500 feet to 2000 feet. I was VFR on top and there were no
holes
anywhere through the fog/clouds/mist.

Prior to the flight, I sumped the wings with no indication of any water.
I
did a normal run up and there were no issues at all. I was running on the
left tank which is what I had run on for the last 1/2 of the flight the
night
before. Left tank had about 20 gallons right tank about 30. Take off was
no
issue and full power was available with a good sounding engine. I found a
hole in the clouds and climbed to 4,500 on a heading direct to Petaluma.
About eight minutes into the flight (from take off), suddenly but not
sudden
like a switch or electrical problem I would guess power output dropped to
around 30% with a decent engine vibration. It felt and acted as if two
sparkplug wires were simultaneously pulled from the plugs. I noticed the
EGT
that I had leaned to 1320 F was now down to below 1000 F. I checked the
mags
and there was no difference in operation between both, 1 or 2. I pushed
the
throttle in full with no effect. I switched tanks to the right wing with
no
effect. I turned on the boost pump with no effect. I opened the power
boost
which bypasses the air filter which resulted in a tiny bit of improvement
maybe getting me up to 35% power. I moved the mixture in full rich and it
smoothed out considerably and I would guess power output moved up to say
45%.
My speed leveled off at around 124 knots from the 151 it was just prior.
I
was able to hold 4,500 feet. EGT rose only about to 1100 F. I contacted
NorCal and advised them of my situation. They were great and offered
vectors
to Modesto that I was right on top of according to the GPS. I advised
them
that it was totally socked in fog that spread about 20 miles in all
directions. After about 30 seconds later I slowly moved the mixture out
and
it began running extremely rough with no increase in EGT so I pushed it
back
in scared that I would make it worse and loose my 45% power output.
NorCal
asked what I wanted to do and as airspeed was being held, it was producing
about 45% power and I was holding altitude I told them I would forge
ahead. I
felt this was less risky than dropping through the fog layer into 3 miles
of
mist visibility with engine problems trying to find a runway with towers
up
around 500 feet in the area. Time is strange and I'm guessing after about
5
minutes of this, I felt the plane pull forward like there was a
significant
power increase and I noticed the EGT move up to 1190 F. I leaned it a
little
and EGT went up to 1200 F max and quickly began to run rough so I slid it
back
in to full rich. After about 3 more minutes I would say the power seemed
to
up around 60% and I tried leaning again. This time it leaned like always
rising to a maximum of about 1410 F before running rough so I backed off
to
run around 1310 F - normal operation. The whole event from the start of
something being wrong to full power being restored was I would say around
10
minutes. Maybe a little less. From that point on it was like nothing was
wrong. Remaining 30 minutes of the flight went without a hitch and the
engine
responded just like it should and always has. I can only think that there
was
some water stuck somewhere in the wing behind one of the baffles and the
engine just had to work through it. I can't think of anything else that
could
have caused this behavior.

The following day I went out and did 10 sumps of each tank and the center
sump. None showed any sign of water. If it was a bad mag I would have
expected to loose the engine completely when I went to mag 1 or mag 2 but
I
didn't. Only thing I can come up with is either water in the tank or an
obstruction in the line.

The engine problem would not have been so critical if I wasn't VFR on top.
Without an engine and VFR on top you have very little options.

Thanks for your opinions and advise. Please post any responses here.

Mooney M20F

PS. Other info is that fuel consumption was normal and I'm at just now at
6
qts of oil remaining after 16.5 hours since last oil change. So that
works
out to be about 11.8 hours per qt. No other indications of problems.
Except
of course the oil and gas dripping out of the plenum drain after stopping
the
engine. Engine has about 80 hours since LMOH and has worked perfectly.

In article , "Morgans" wrote:

"Paul Smedshammer" wrote

This is a bit long winded but I'm looking for qualified opinions as to
what
might have happed to an almost total loss of power while in cruise flight
in
my Mooney M20F.

Giant snip

It sounds almost like conditions were perfect for induction ice, but is that
possible with this type of injection? Is there any provision for heat, or
just unheated alternate air?

This, from a definite unqualified person. Me. g

The Mooney M20F has a fuel injection system so there is no carburetor nor
'carb heat'. I'm open to anything that could have caused this. Ice is a
definite possibility in the fuel system. It hadn't rained but the overnight
stay at the airport I left from had the most intense ground fog I have ever
experienced. I would say there was 50 foot visibility on the ground that
lasted a good 10 hours. I was thinking this could have caused some
condensation to pool water on the inside of fuel tanks. Maybe after flying
out, that condensation shook loose from the walls and pooled up and got sucked
in.

That being said, I was well above moisture and it was over 65 degrees F at the
4,500 feet I was at. The weather breifer made no mention of icing conditions
and I didn't see any on the DUATs reports. I was VFR on top for the 30 miles
that overcast was spread. This really opened my eyes as this problem happed
just about 8 minutes into the 30 miles. It couldn't have happened at a worse
time. I was very lucky I had the altitude and that it cleared up and normal
power was restored. If the problem persisted, I would have definitely bent
the plane up as a minimum and at the worst been killed and possibly cause bad
results to folks on the ground. I definitely have a greater respect for VFR
on top.

Paul

"Paul Smedshammer" wrote

The Mooney M20F has a fuel injection system so there is no carburetor nor
'carb heat'.

Paul

Right, I know it is fuel injected, but it is a "throttle body" type, rather
than individual injectors for each cylinder, isn't it?

It seems to me that if it is this type, a possibility of a temperature drop
from evaporating fuel could still open up an opportunity for water vapor in
the air to freeze, in the right conditions.
--
Jim in NC

On Mon, 13 Dec 2004 03:48:36 GMT, (Paul
Smedshammer) wrote:

This is a bit long winded but I'm looking for qualified opinions as to what
might have happed to an almost total loss of power while in cruise flight in
my Mooney M20F.

Do you have individual cylinder EGT's?

It sure sounds like a problem with fuel flow. When I had a similar problem
it was due to a partially clogged fuel injector, but there could have been
junk in the lines also, or possible on the fuel screen.

Mine did not clear spontaneously, though.

Unless something else comes to mind, I would check the fuel system
carefully, including the screen. Sometimes when the tank sealant starts to
break down, it can cause these kinds of problems.

Also, with regard to induction ice, check the alternate air valve.
Sometimes that valve can jam. I think there was an AD on it some time ago.
(I can't recall if it applied to the F's).


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"Ron Rosenfeld" wrote:

It sure sounds like a problem with fuel flow.

Wouldn't a fuel restriction make the EGT go up?
--
Dan
C-172RG at BFM

On Mon, 13 Dec 2004 07:42:08 -0600, "Dan Luke" wrote:


"Ron Rosenfeld" wrote:

It sure sounds like a problem with fuel flow.

Wouldn't a fuel restriction make the EGT go up?

If you lean your engine until it starts to run rough, what happens (both to
TIT as well as to the individual EGT's), is that the EGT initially rises,
then it reaches a peak and begins to fall.

So what happens to the EGT will depend on where you are on that curve, when
the engine begins to run rough.

I have had problems, over the years, with clogged injector; clogged fuel
line; and clogged fuel servo. In all of those instances, the EGT for the
affected cylinder(s) went down when engine roughness was noted. Except for
the fuel servo when the problem became evident on takeoff and I was
concentrating on landing, rather than looking at EGT's.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

In article , emove (AJW) wrote:

It sounds like something caused you to lose fuel flow -- did you notice the
fuel pressure gauge?


Fuel pressure was in the green and appeared to be normal through the whole
event. I only have one EGT and CHT gauge so I only know what was going on
with the one cylinder.

I have received many opinions and the two that seem the most plausible are
induction icing and fuel contamination. Bummer is that I don't know how to
verify either. I would sure like to get my confidence level in this engine
back up to where it was before the event.

I'm going to have my mechanic check over the fuel filter screen and anything
else he might find. Problem is, that it ran perfectly for the remaining 30
minutes of the flight. And I went out the next day and did a full run up on
both tanks and everything seems totally normal. I would have felt better if I
could have at least found some water in the tanks.

Paul

In article , "Morgans" wrote:

"Paul Smedshammer" wrote

The Mooney M20F has a fuel injection system so there is no carburetor nor
'carb heat'.

Paul

Right, I know it is fuel injected, but it is a "throttle body" type, rather
than individual injectors for each cylinder, isn't it?

It seems to me that if it is this type, a possibility of a temperature drop
from evaporating fuel could still open up an opportunity for water vapor in
the air to freeze, in the right conditions.

The IO-360A1A has individual injectors to for each cylinder. However, I'm
still learning about the potential for induction icing to occur and I think you
are right that this is a definite possibility.

But as somebody mentioned in another post, if induction icing were the cause I
should have seen a rise in the EGT as the fuel flow became restricted instead
of a sudden drop from 1310 to under 1000 F.

The most plausible cause that many have suggested so far is that there was
water mixed in with the fuel. When I enriched the mixture it let a larger
volume of the fuel/water mixture in which resulted in a slightly smoother and
more powerfully running engine. Which would also account for the lower EGT.
Then as this fuel/water mixture worked its way through, normal operation was
restored when the fuel/water mixture returned to just fuel. I really hope
this was the cause but I'm still open for it being something else that I need
to be aware of.

I still get sick thinking about this happening on climb out with a broken
cloud and fog deck at 800 feet. As it took about 8 minutes to clear at full
throttle in cruise there is no way it would have cleared during the climb out.
And what is worse, if it was water in the fuel, I could have sucked in a full
slug of water killing the engine completely. This was a serious learning
experience for me. Just glad I'm around to apply it.

Paul