IO-540 mystery

Our club's PA32R-300 has an IO-540 with lots and lots of hours on it.
After 20+ years, at this year's annual the compression was down a few
pounds on a couple of the cylinders, and the mechanic said he really has
his doubts about it passing next year's annual. That might be
significant, or it might not.

Twice this year, while people have been flight training in it (I was doing
a BFR this spring, another pilot was checking out in the plane for the
first time a few weeks ago), the engine has been running fine and on
rollout afterwards the engine died and couldn't be restarting. Both times
it was after doing some air-work (stalls, steep turns, etc) and then a
couple of touch and goes. Nobody has had any problems in a normal point
to point flight, although we've had the normal problems with hot starting
that's endemic to fuel injected aviation engines.

The last time it happened, the engine died at the airport where our
mechanic is based, and he pulled the plugs and said they weren't fouled
and they were dry (so the problem restarting wasn't that he flooded it).
Based on a suggestion here, I had them check the fuel pressure, and it
seems fine. Could it be vapour lock? Any other suggestions?

--
Paul Tomblin http://blog.xcski.com/
"Once you have an emergency, the airplane belongs to the insurance company.
Concentrate on saving people on the ground, your passengers, and yourself,
in that order. Saving the plane is not on the list."

"Paul Tomblin" wrote in message ...
Our club's PA32R-300 has an IO-540 with lots and lots of hours on it.

seems fine. Could it be vapour lock? Any other suggestions?

--
Paul Tomblin http://blog.xcski.com/


Yes...check the electric fuel pump?

Hey Paul,
Ask a guy who currently has 2 cylinders in the back seat of his Chevy Tahoe
about low compressions #1 and #2 on our left engine were under 20 lbs
when we checked them this weekend after being in the mid 70's last year.
JPI data didn't show anything significant during cruise, but we see some
excessive EGT drop with major power reductions on the #1. Valves move well
and look good, but there's plenty of buildup. So we'll send them in to have
everything cleaned up, the seats ground, valves lapped, guide reamed, and
what ever else they recommend. These are Lycoming nitride, what cylinders
are on the club Lance?

dieing on rollout. I've had this occur twice with the Aztec, it makes a
twin fun to taxi. Both times it was the right engine after normal approach
and landing on a very hot (+90) day. I asked a couple A&P's about it and
they both said that if the rpms at idle are normal when the engine is warm,
then suspect fuel pressure.

No answers, just general questions.
Do you normally turn the electric fuel pump on for maneuvers and leave it on
for touch and goes? Can you discern any relationship between the electric
fuel pump operation and the engine dieing, such as it dieing shortly after
the pump is switched off while at low rpm? When was the last time the fuel
pressure was checked on the electric pump? Any sign of fuel leaking from
the mechanical pump's vent/drain? Could your mechanical fuel pump be weak?

I've got a Lance manual in this PC somewhere. If you need any specs let me
know. When I have a minute, I'll look at the troubleshooting sections.

Jim

"Paul Tomblin" wrote in message
...
Our club's PA32R-300 has an IO-540 with lots and lots of hours on it.
After 20+ years, at this year's annual the compression was down a few
pounds on a couple of the cylinders, and the mechanic said he really has
his doubts about it passing next year's annual. That might be
significant, or it might not.

Twice this year, while people have been flight training in it (I was doing
a BFR this spring, another pilot was checking out in the plane for the
first time a few weeks ago), the engine has been running fine and on
rollout afterwards the engine died and couldn't be restarting. Both times
it was after doing some air-work (stalls, steep turns, etc) and then a
couple of touch and goes. Nobody has had any problems in a normal point
to point flight, although we've had the normal problems with hot starting
that's endemic to fuel injected aviation engines.

The last time it happened, the engine died at the airport where our
mechanic is based, and he pulled the plugs and said they weren't fouled
and they were dry (so the problem restarting wasn't that he flooded it).
Based on a suggestion here, I had them check the fuel pressure, and it
seems fine. Could it be vapour lock? Any other suggestions?

--
Paul Tomblin http://blog.xcski.com/
"Once you have an emergency, the airplane belongs to the insurance
company.
Concentrate on saving people on the ground, your passengers, and yourself,
in that order. Saving the plane is not on the list."

I saw the same behavior on my IO470's. Turned out the engine fuel pressure
needed adjustment at idle.

In a previous article, "Blueskies" said:
"Paul Tomblin" wrote in message
...
Our club's PA32R-300 has an IO-540 with lots and lots of hours on it.
seems fine. Could it be vapour lock? Any other suggestions?

Yes...check the electric fuel pump?

As I said in the post above:
Based on a suggestion here, I had them check the fuel pressure, and it
seems fine.

It was 22psi with just the engine driven pump, and 23psi with the electric
fuel pump on.

--
Paul Tomblin http://blog.xcski.com/
"Belligerent Design: The theory that life was put on this planet by an
external sentient force just to **** me off." - Lore Brand Comics

In a previous article, "Jim Burns" said:
what ever else they recommend. These are Lycoming nitride, what cylinders
are on the club Lance?

I think they're nitride as well.

Do you normally turn the electric fuel pump on for maneuvers and leave it on
for touch and goes? Can you discern any relationship between the electric

Yes.

fuel pump operation and the engine dieing, such as it dieing shortly after
the pump is switched off while at low rpm?

No, in the case when I was flying, I'd touched down, was rolling out
without touching the throttle, and when I turned off on the taxiway it
just died.

When was the last time the fuel pressure was checked on the electric
pump?

About 6 hours ago.

Any sign of fuel leaking from the mechanical pump's vent/drain?

No.

Could your mechanical fuel pump be weak?

Don't think so. When we tested the fuel pressure this morning, it was
22psi on the engine pump, 23psi on the electric fuel pump, and almost no
variation at different throttle/mixture settings.



--
Paul Tomblin http://blog.xcski.com/
"Faced with the prospect of rereading this book, I would rather have my brains
ripped out by a plastic fork." - Charles Cooper reviews the new Gates book.
http://zdnet.com.com/2100-1107-514105.html

Idle mixture????

Paul Tomblin wrote:
Our club's PA32R-300 has an IO-540 with lots and lots of hours on it.
After 20+ years, at this year's annual the compression was down a few
pounds on a couple of the cylinders, and the mechanic said he really has
his doubts about it passing next year's annual. That might be
significant, or it might not.

Twice this year, while people have been flight training in it (I was doing
a BFR this spring, another pilot was checking out in the plane for the
first time a few weeks ago), the engine has been running fine and on
rollout afterwards the engine died and couldn't be restarting. Both times
it was after doing some air-work (stalls, steep turns, etc) and then a
couple of touch and goes. Nobody has had any problems in a normal point
to point flight, although we've had the normal problems with hot starting
that's endemic to fuel injected aviation engines.

The last time it happened, the engine died at the airport where our
mechanic is based, and he pulled the plugs and said they weren't fouled
and they were dry (so the problem restarting wasn't that he flooded it).
Based on a suggestion here, I had them check the fuel pressure, and it
seems fine. Could it be vapour lock? Any other suggestions?

Paul Tomblin wrote:
In a previous article, "Jim Burns" said:

what ever else they recommend. These are Lycoming nitride, what cylinders
are on the club Lance?


I think they're nitride as well.


Do you normally turn the electric fuel pump on for maneuvers and leave it on
for touch and goes? Can you discern any relationship between the electric


Yes.


fuel pump operation and the engine dieing, such as it dieing shortly after
the pump is switched off while at low rpm?


No, in the case when I was flying, I'd touched down, was rolling out
without touching the throttle, and when I turned off on the taxiway it
just died.


When was the last time the fuel pressure was checked on the electric
pump?


About 6 hours ago.


Any sign of fuel leaking from the mechanical pump's vent/drain?


No.


Could your mechanical fuel pump be weak?


Don't think so. When we tested the fuel pressure this morning, it was
22psi on the engine pump, 23psi on the electric fuel pump, and almost no
variation at different throttle/mixture settings.



My IO-360 did this a while back. Needed the fuel servo overhauled.

In a previous article, The Visitor said:
Idle mixture????

When it happened to me, I was rolling out after landing, so the mixture
was full rich.


--
Paul Tomblin http://blog.xcski.com/
Windows gives you a nice view of clouds so you can't see any potentially
useful boot time messages.
-- Bill Hay

check the idle mixture. the lycoming manual will detail the procedure. the
left engine on my twin does that when the idle mix is not set properly.

full rich and hot temps, sounds like the problem.


R. Burns


"Paul Tomblin" wrote in message
...
In a previous article, The Visitor said:
Idle mixture????

When it happened to me, I was rolling out after landing, so the mixture
was full rich.


--
Paul Tomblin http://blog.xcski.com/
Windows gives you a nice view of clouds so you can't see any potentially
useful boot time messages.
-- Bill Hay