Ok, so how *do* you hotstart your IO-540?

I know that hot starting IO-540s is a subject for considerable debate. I
was taught a method that I was told worked 100% of the time[1], and up
until yesterday it had. But yesterday, after flying for an hour and then
sitting in the hot sun for half an hour waiting for customs, I couldn't
restart the Lance and had to have it towed back to the tie down area.

So what would you do in that situation?

[1] Leave the throttle, mixture and prop alone from when you shut down.
Turn on the fuel pump, and crank. When it catches, quickly advance the
mixture to full, and once it stops spluttering lean it out.

--
Paul Tomblin http://blog.xcski.com/
"Zero Tolerance" in this case meaning "We're too stupid to be able to
apply conscious thought on a case-by-case basis".
-- Mike Sphar

"Paul Tomblin" wrote:

I know that hot starting IO-540s is a subject for considerable debate. I
was taught a method that I was told worked 100% of the time[1], and up
until yesterday it had. But yesterday, after flying for an hour and then
sitting in the hot sun for half an hour waiting for customs, I couldn't
restart the Lance and had to have it towed back to the tie down area.

So what would you do in that situation?

Good question. I've had one of the beasts for a month now, and it's a crap
shoot every time.


[1] Leave the throttle, mixture and prop alone from when you shut down.
Turn on the fuel pump, and crank. When it catches, quickly advance the
mixture to full, and once it stops spluttering lean it out.


Haven't tried that, yet. How long do you leave the pump on?



Here's another method from one of the Cessna Pilots Ass'n forums:

Hot start:

Throttle in 1/4" from idle.
Mixture cutoff
Fuel pump on
Mixture full forward until fuel flow just registers (about a long
one-one-thousand)
Mixture cutoff
Fuel pump off
Crank - after about six to ten blades (3-blade prop) it will fire -
immediately come foreward to full rich.

Shorten or lengthen the priming time from one to three seconds depending on
time since shut-down.


--
Dan
T-182T at BFM

In a previous article, "Dan Luke" said:
"Paul Tomblin" wrote:
[1] Leave the throttle, mixture and prop alone from when you shut down.
Turn on the fuel pump, and crank. When it catches, quickly advance the
mixture to full, and once it stops spluttering lean it out.


Haven't tried that, yet. How long do you leave the pump on?

Until it's started. Because the mixture is still at cut-off, no fuel is
flowing.

Hot start:

Throttle in 1/4" from idle.
Mixture cutoff
Fuel pump on
Mixture full forward until fuel flow just registers (about a long
one-one-thousand)
Mixture cutoff
Fuel pump off
Crank - after about six to ten blades (3-blade prop) it will fire -
immediately come foreward to full rich.

Shorten or lengthen the priming time from one to three seconds depending on
time since shut-down.

That's how I cold start it - the only difference with hot starting is that
I don't do the "mixture full forward until the fuel flow just registers".


--
Paul Tomblin http://blog.xcski.com/
So I was reading Twelfth Night ... and would you believe that the I LOVE YOU
hoax is the exact same trick Shakespeare uses to point out what an arrogant,
self-absorbed fool Malvolio is? -- Julia McKinnell

"Paul Tomblin" wrote:

How long do you leave the pump on?

Until it's started. Because the mixture is still at cut-off, no fuel is
flowing.

??

Then why leave it on?

--
Dan
T-182T at BFM

"Paul Tomblin" wrote:

How long do you leave the pump on?
Until it's started. Because the mixture is still at cut-off, no fuel is
flowing.

Dan Luke wrote:
??
Then why leave it on?

Fuel is flowing from the tanks to the spider, from the spider it is
going back to the tank via the return line. As the mixture is advanced,
fuel will flow from the spider to the cylinders.

"john smith" wrote:

How long do you leave the pump on?
Until it's started. Because the mixture is still at cut-off, no fuel is
flowing.

Dan Luke wrote:
??
Then why leave it on?

Fuel is flowing from the tanks to the spider, from the spider it is going
back to the tank via the return line.

AIUI, that's true on Continentals but not on Lycomings. According to
discussions I've seen on the Cessna Pilots Assn. forums, closing the mixture
control dead-heads the pump.

Anybody got an authoritative cite on this?

--
Dan
T-182T at BFM

On Jul 16, 10:06 pm, "Dan Luke" wrote:
"Paul Tomblin" wrote:

How long do you leave the pump on?



Until it's started. Because the mixture is still at cut-off, no fuel is
flowing.

??

Then why leave it on?

--
Dan
T-182T at BFM

Hi, I'm a student A&P (Commercial, instrument pilot) and recently
learned that the fuel vapor in the line needs to be purged to assist
starting fuel-injected engines, meaning the line between the tank and
the "spider" fuel distributor. This is why the mixture is left closed,
to clean out the line of the hot fuel vapor that will make starting
difficult.
The Lycoming manual for the fuel injectors we were working with have a
humorous, yet informative and accurate description and remedy for the
problem of hot starting fuel-injected engines.
Now I know why the old Arrow I did my commercial training in was so
hard to start after shutting down in the hot Texas Summer.

Ricky (WOW, I'm already teaching something I learned last semester!)

On Jul 16, 10:06 pm, "Dan Luke" wrote:
"Paul Tomblin" wrote:

How long do you leave the pump on?



Until it's started. Because the mixture is still at cut-off, no fuel is
flowing.

??

Then why leave it on?

--
Dan
T-182T at BFM

Oops, I think I meant fuel flows from the tank to the pump & back via
the return line which purges the line of the hot vapor.
Well, I made an A in the class, anyway.

Ricky

In article ,
(Paul Tomblin) wrote:

So what would you do in that situation?

[1] Leave the throttle, mixture and prop alone from when you shut down.
Turn on the fuel pump, and crank. When it catches, quickly advance the
mixture to full, and once it stops spluttering lean it out.

The PA32-300 I fly can be fun to start when it is hot.
It depends upon how long it has been sitting since it was shut down.
For a short duration, what you described above may work.

The first thing I do is park the aircraft so the nose is pointing into
the wind. After shut down, open the oil door atop the cowl.

Flooded procedure has been my most successful procedure.

Something else to try is...
Throttle full forward
Mixture closed
Fuel pump ON for 30 seconds (no fuel goes to the engine but passes
through the fuel line to the engine then back through the return line to
the tank; this cools the fuel line and purges any bubbles in the line;
that's the theory)
Normal start procedure

One of the things I learned when flying an IO-320 in a homebuilt
amphibean was that there were "sweet spot" throttle and mixture postions
(right combination of air and fuel) where the engine would start up
immediately. These were learned through trial and error.

john smith wrote:


The PA32-300 I fly can be fun to start when it is hot.
It depends upon how long it has been sitting since it was shut down.
For a short duration, what you described above may work.

The first thing I do is park the aircraft so the nose is pointing into
the wind. After shut down, open the oil door atop the cowl.


With the Continental 520 in my Bo you want to park facing downwind so
the wind can blow up into the cowl flaps to help cool the fuel pump.
The fuel boiling in the engine driven fuel pump is what causes the hot
start problems.