Hot and flooded engine starting.

[Robin]

Welcome Matt

I think Antoine has summed it up nicely.

COLD STARTS as Antoine suggested follow the AFM. I wait for the MFD to power up, switch to the engine page. Open the throttle one inch, advance the mixture counting to 5, and you will see the fuel flow increase to 5 to 6 GPH. Mixture ICO -idle cut off.

Bring the throttle back to under half an inch. Start.

HOT START

I follow Antoine's procedure, it works as he says 99% of the time. I agree with Rick, that hot starts are better with throttle more open. I find that it takes some co-ordination to advance the mixture, whilst transfering my left hand from the starter key to the throttle which needs to be reduced quickly once the engine fires.

A question, as flying in Australia we sometimes have very hot days 35 to 42 Celsius, IF the mixture is ICO, then using the fuel pump should just pressurize the fuel lines to the injectors, and nothing should enter the cylinders. Previously flying a Piper Arrow we would always get vapour block on hot days...

FLOODED STARTS - throttle wide open. Allow to drain. Go and have a cup of coffee for half an hour and come back later.

LEAN AFTER START AND ON TAXI

Could not agree more. As Antoine says, lean until the CHT rise. Much less fouling with this method.

Safe flying

Robin

[Graham]

This is what I was told when I checked out in London. It hasn't failed yet in almost 200hrs.

Cold Start
Throttle Open 3cm
Fuel Pump On
Mixture Rich 3-5s then Idle Cut-Off (here you watch the fuel flow until it just about stops climbing and then idle cut-off)
Throttle Just Above Idle
Ignition Switch Start
Mixture Advance to Rich

Warm Start (Oil Temp > 100F)
Throttle Open 3cm
Fuel Pump On
Mixture Rich 1 sec then Idle Cut-Off
Throttle Just Above Idle
Ignition Switch Start
Mixture Advance to Rich

Abnormal Procedures: Flooded Start
Mixture Idle Cut-Off
Fuel Pump Off
Throttle At Mid-Position
Ignition Switch Start
Throttle Briskly Aft to 1000 RPM
Mixture Advance to Rich

[Bob C]

I, like many others, had to learn this the hard way and needed to do several flooded engine procedures. When hot, like going to the self-serve fuel dock, what seems to be working good for me is to leave mixture closed, open throttle 1/3 of the way, hit the starter and wait for the engine to start, then move mixture briskly to 2/3 while reducing throttle to a reasonable level, as it will be to fast -- all while having the brakes engaged. Having had to pay for a recent boost pump, I'm not anxious to use it for other than T/O L/D if I can help it. I also installed the fine wire plugs and highly recommend them. It will save you trips to the local mechanic to clean them. For cold start, 3 seconds of rich with the boost pump on works every time for me.

[CBeak]

Just reviewing this old thread. I tend to fill the tanks after landing, before I taxi to the hangar, and I’m having hot engine start problems. Not too surprising since my last 14 yrs were spent starting a carbureted version of the very same engine. That one was hard to start cold, but a breeze when it was hot.

[astaib]

Cold: wot / max rich : pump 5 sec. Then full lean, 1cm throttle, ignition, then when engine fires :full rich.

Hot: wot / max lean. Ignition, when engine fires (a little bit longer than when cold), full rich and throttle idle (fast enough not to have high rpm).

Easy.

[Davestation]

Certainly if the airplane has flown in the last 45 to 60 minutes, priming is not required. Due to the potential for vapor lock, I turn on the boost pump, but do not open the mixture until the engine fires. After a hot restart, I have noticed that my engine runs smoother if I leave the boost pump on during taxi.

I'm not sure how vapor lock is averted if you have the boost pump on but your mixture is held at cutoff. The engine can only be firing on a drop of residual fuel still in the cylinders, meanwhile the fuel still sitting in the lines has come to a nice boil, no?