Starting Engine Question (O-320, Warrior)

My question refers to Warrior IIs, but could be about other
Lycoming O-320 and O-360 engines with electric fuel pumps too.

I've noticed checklists on some Warriors tell you to turn the
electric fuel pump ON and leave it on for starting, and others
tell you to turn the fuel pump ON, check pressure, then OFF
before starting.

The actual P.O.H. I've seen says to turn the fuel pump on before
start but doesn't even mention to check the fuel pressure to make
sure that the electric pump works. It doesn't say when to turn
the fuel pump off, except during the run-up to turn it off so the
pressure can be checked. All in all, the checklists in the
actual P.O.H. aren't very impressive and seem to leave a lot of
important stuff out. They don't even remind you to shut off the
cabin heat/defrost before starting to protect you in case there
is a fire during start.

So why the different schools of thought? It doesn't seem
necessary to leave the pump on for taxi, as the POH suggests.
But should the fuel pump be on while cranking? What does
everybody do?

Pump off - Throttle Full Open - Mixture Full Rich
Pump on (for 4 sec) then Pump Off
Throttle 1/2" - Mixture Idle Cut Off
Crank
Mixture Fully Rich when engine fires (and starts to run)


"Lisa" wrote in message ...
My question refers to Warrior IIs, but could be about other
Lycoming O-320 and O-360 engines with electric fuel pumps too.

I've noticed checklists on some Warriors tell you to turn the
electric fuel pump ON and leave it on for starting, and others
tell you to turn the fuel pump ON, check pressure, then OFF
before starting.

The actual P.O.H. I've seen says to turn the fuel pump on before
start but doesn't even mention to check the fuel pressure to make
sure that the electric pump works. It doesn't say when to turn
the fuel pump off, except during the run-up to turn it off so the
pressure can be checked. All in all, the checklists in the
actual P.O.H. aren't very impressive and seem to leave a lot of
important stuff out. They don't even remind you to shut off the
cabin heat/defrost before starting to protect you in case there
is a fire during start.

So why the different schools of thought? It doesn't seem
necessary to leave the pump on for taxi, as the POH suggests.
But should the fuel pump be on while cranking? What does
everybody do?

Hi Lisa,
You should have the electric fuel pump on for start up. Then shut it off
right after start up to check for normal pressure from the engine driven
pump as you check for the oil pressure once the engine is idling at about
1000 rpm. The next time I turn the electric pump back on is when I take the
active runway for departure.
Hope this helps.

David Smith



"Lisa" wrote in message ...
My question refers to Warrior IIs, but could be about other
Lycoming O-320 and O-360 engines with electric fuel pumps too.

I've noticed checklists on some Warriors tell you to turn the
electric fuel pump ON and leave it on for starting, and others
tell you to turn the fuel pump ON, check pressure, then OFF
before starting.

The actual P.O.H. I've seen says to turn the fuel pump on before
start but doesn't even mention to check the fuel pressure to make
sure that the electric pump works. It doesn't say when to turn
the fuel pump off, except during the run-up to turn it off so the
pressure can be checked. All in all, the checklists in the
actual P.O.H. aren't very impressive and seem to leave a lot of
important stuff out. They don't even remind you to shut off the
cabin heat/defrost before starting to protect you in case there
is a fire during start.

So why the different schools of thought? It doesn't seem
necessary to leave the pump on for taxi, as the POH suggests.
But should the fuel pump be on while cranking? What does
everybody do?

Cockpit Colin wrote:

Pump off - Throttle Full Open - Mixture Full Rich
Pump on (for 4 sec) then Pump Off
Throttle 1/2" - Mixture Idle Cut Off
Crank
Mixture Fully Rich when engine fires (and starts to run)

Is that the procedure in your POH? Except for the throttle setting, your
description most closely matches the Starting Engine when Flooded procedure in
my POH. The normal cold & warm starts don't include cranking with Mixture at
Cut-Off.

Hi Lisa.

I agree that the actual POH leaves a lot to be desired. We check for
pressure from the electric fuel pump during preflight. Master ON, Check Fuel
Gauges, Fuel Pump ON, check pressure, Fuel Pump OFF, Master OFF.

We do use the auxilliary fuel pump for starting the engine - don't remember
now why exactly, but I believe it's just to ensure fuel flow during the
start. Cranking the engine w/o enough fuel (too lean) is worse than getting
it started and then having it kill when the aux pump is turned off. Less
risk of detonation on startup, I guess (and I am guessing).

Once the engine is started. we do not use the auxiliary pump again until
pretakeoff (it is off for taxiing and the runup). It stays on through
takeoff until 500' AGL.

Thinking about your comment about shutting off cabin heat/defrost before
starting, I could see this being an issue in airplanes where the carburetor
is mounted underneath the engine, as flames could travel up into the cabin
air duct. The way the carburetor is mounted on the Warrior's engine, I think
this is far less likely to happen. I won't say it couldn't, but I just don't
see how, unless you had a ruptured fuel line that covered the inside of the
cowling - something that would create a larger fireball than just a flooded
carburetor.





"Lisa" wrote in message ...
My question refers to Warrior IIs, but could be about other
Lycoming O-320 and O-360 engines with electric fuel pumps too.

I've noticed checklists on some Warriors tell you to turn the
electric fuel pump ON and leave it on for starting, and others
tell you to turn the fuel pump ON, check pressure, then OFF
before starting.

The actual P.O.H. I've seen says to turn the fuel pump on before
start but doesn't even mention to check the fuel pressure to make
sure that the electric pump works. It doesn't say when to turn
the fuel pump off, except during the run-up to turn it off so the
pressure can be checked. All in all, the checklists in the
actual P.O.H. aren't very impressive and seem to leave a lot of
important stuff out. They don't even remind you to shut off the
cabin heat/defrost before starting to protect you in case there
is a fire during start.

So why the different schools of thought? It doesn't seem
necessary to leave the pump on for taxi, as the POH suggests.
But should the fuel pump be on while cranking? What does
everybody do?

Lisa wrote:
My question refers to Warrior IIs, but could be about other
Lycoming O-320 and O-360 engines with electric fuel pumps too.

I've noticed checklists on some Warriors tell you to turn the
electric fuel pump ON and leave it on for starting, and others
tell you to turn the fuel pump ON, check pressure, then OFF
before starting.

The actual P.O.H. I've seen says to turn the fuel pump on before
start but doesn't even mention to check the fuel pressure to make
sure that the electric pump works. It doesn't say when to turn
the fuel pump off, except during the run-up to turn it off so the
pressure can be checked. All in all, the checklists in the
actual P.O.H. aren't very impressive and seem to leave a lot of
important stuff out. They don't even remind you to shut off the
cabin heat/defrost before starting to protect you in case there
is a fire during start.

So why the different schools of thought? It doesn't seem
necessary to leave the pump on for taxi, as the POH suggests.
But should the fuel pump be on while cranking? What does
everybody do?


As per our club's cheklist, it goes:

-- Pump on
-- Pressure in the green arc
-- Pump Off
-- Throttle - set for 1000rpm
..
..
etc.


I like it for two reasons.. The POH in our aircraft state the electric
fuel pump is a redundancy in case of mechanical fuel pump failure...

May as well check it as early as possible in the start, rather than wait
for run-ups or after t/o to realise you have an unserviceable unit.

Checking the electric fuel pump during start checks - for the same reason..

Cheers,
NCM

"Lisa" wrote in message ...
My question refers to Warrior IIs, but could be about other
Lycoming O-320 and O-360 engines with electric fuel pumps too.

I've noticed checklists on some Warriors tell you to turn the
electric fuel pump ON and leave it on for starting, and others
tell you to turn the fuel pump ON, check pressure, then OFF
before starting.

The actual P.O.H. I've seen says to turn the fuel pump on before
start but doesn't even mention to check the fuel pressure to make
sure that the electric pump works. It doesn't say when to turn
the fuel pump off, except during the run-up to turn it off so the
pressure can be checked. All in all, the checklists in the
actual P.O.H. aren't very impressive and seem to leave a lot of
important stuff out. They don't even remind you to shut off the
cabin heat/defrost before starting to protect you in case there
is a fire during start.

So why the different schools of thought? It doesn't seem
necessary to leave the pump on for taxi, as the POH suggests.
But should the fuel pump be on while cranking? What does
everybody do?

the only reason for turning the pump on before start is to check the
pressure to ensure the electric pump is working. once the engine is running
there is no pressure difference when you turn on the electric pump so you
cant tell if its working. I turn it on before start, check the pressure
then turn it off before starting the engine. I turn it back just prior to
commencing take off run.
then turn it off again ( and check pressure again) at 500' AGL

Terry

This sounds like the procedure for a fuel injected engine.
The fuel pump in the carbureted engine has no effect on
engine starting except to make sure that about three pounds of fuel pressure
is obtained at the carb inlet.
This is a pressure regulated pump and will stop pumping
when the set pressure is reached. The method in the
manual usually is the best.

Good luck,

Skyking
"Lisa" wrote in message
...


Cockpit Colin wrote:

Pump off - Throttle Full Open - Mixture Full Rich
Pump on (for 4 sec) then Pump Off
Throttle 1/2" - Mixture Idle Cut Off
Crank
Mixture Fully Rich when engine fires (and starts to run)

Is that the procedure in your POH? Except for the throttle setting, your
description most closely matches the Starting Engine when Flooded
procedure in
my POH. The normal cold & warm starts don't include cranking with Mixture
at
Cut-Off.

For a carburetor engine the electric fuel pump is only needed to fill the
bowl before cranking...
The check list you give is for fuel injected engines...

denny

"Cockpit Colin" wrote in message
...
Pump off - Throttle Full Open - Mixture Full Rich
Pump on (for 4 sec) then Pump Off
Throttle 1/2" - Mixture Idle Cut Off
Crank
Mixture Fully Rich when engine fires (and starts to run)

I turn the fuel pump on until I get fuel pressure .. then turn it off. Then
I
start the engine and taxi. That way I can make sure the engine driven pump
is working. I use the electric pump
for takeoff, landing, and when changing fuel tanks.




"Lisa" wrote in message ...
My question refers to Warrior IIs, but could be about other
Lycoming O-320 and O-360 engines with electric fuel pumps too.

I've noticed checklists on some Warriors tell you to turn the
electric fuel pump ON and leave it on for starting, and others
tell you to turn the fuel pump ON, check pressure, then OFF
before starting.

The actual P.O.H. I've seen says to turn the fuel pump on before
start but doesn't even mention to check the fuel pressure to make
sure that the electric pump works. It doesn't say when to turn
the fuel pump off, except during the run-up to turn it off so the
pressure can be checked. All in all, the checklists in the
actual P.O.H. aren't very impressive and seem to leave a lot of
important stuff out. They don't even remind you to shut off the
cabin heat/defrost before starting to protect you in case there
is a fire during start.

So why the different schools of thought? It doesn't seem
necessary to leave the pump on for taxi, as the POH suggests.
But should the fuel pump be on while cranking? What does
everybody do?