Hot Start Phobia

Par129

Par129

Filing Flight Plan
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Par129
For the last 10 years or so I've owned a Cessna 182S with a Lycoming IO-540. Overall, I love the plane and engine, however I have one issue that is driving me insane. I cannot seem to come up with a reliable hot start procedure... One day it will start on the first rotation of the prop, then the next day nothing will work short of waiting 10-15 minutes and trying again. I have had the engine clearly flooded and tried Hot Start Procedure #1 & #3 with no luck. Any advice or recommendations are appreciated. I should add that on cold starts it starts immediately every time and quickly. What am I missing here?

Cold Start Procedure (POH)
Throttle: OPEN ¼”
Propeller: HIGH RPM
Mixture: IDLE CUT OFF
Propeller Area: CLEAR
Master: ON
Fuel Pump: ON
Mixture: ADVANCE UNTIL FLOW, IDLE CUT OFF
Fuel Pump: OFF
Ignition Switch : START
Mixture: ADVANCE TO RICH WHEN ENGINE FIRES

Hot Start Procedure #1 (POH)
Throttle: OPEN ¼”
Propeller: HIGH RPM
Mixture: IDLE CUT OFF
Propeller Area: CLEAR
Master: ON
Ignition Switch : START
Mixture: ADVANCE TO RICH WHEN ENGINE FIRES

NOTE: If engine floods, place mixture in idle cut off, open throttle 1/2 to full, and crank engine. When engine fires, advance mixture to full rich and retard throttle promptly.

Shutdown/Hot Start Procedure #2
Throttle: 1000 RPM PRIOR TO PULLING MIXTURE
Mixture: IDLE CUT OFF, DON’T TOUCH ANYTHING
Magnetos: START
Engine Catch: MIXTURE RICH

Hot Start Procedure #3
Throttle: FULL OPEN
Mixture IDLE CUT OFF
Fuel Pump ON
Mixture FORWARD 1-2 SECONDS
Magnetos START
Engine Catches MIXTURE FORWARD, THROTTLE IDLE
Fuel Pump OFF
 
Long time lurker, first time poster. Might be able to help.

When starting again within 2 hours from shut-down, cowl-flaps open, and open the oil door on top of the cowl to help dissipate heat.

My hot start procedure (works for me 9/10 times):
-Do not prime
-Throttle 1/4 open
-Mixture cut off
-Mags to start
-Mixture slowly in,
-When it catches, left hand from key to fuel pump and turn on for 3-5 seconds.

Works wonderfully. Few times it does not work, I let the starter cool down for a few minutes and do the same process as above, but with throttle opened further. This has worked every time for me.
 
I've flown a Cessna 182T for the last 4 years, primarily throughout the midwest and very often in the dead of summer. I have no concerns about hotstarts with the following procedure. BTW, this same approach works reliably with my IO-360 Husky and is my go to on any hot start, but especially on those 100 degree plus days.

- DO NOT PRIME
-Throttle set to 1,000 RPM (basically set it at shutdown and no need to worry about it on start up)
-Mixture OFF
-Crank it over until it starts...usually 3-5 rotations
-Mixture full rich immediately after it starts.

That's it, very easy and works everytime. I too went through all the complicated hot start procedures and ultimately found that there was plenty of fuel in the system and the other approaches ultimately flooded the engine with even more fuel. Hope this works for you.
 
My io540 starts reliably using the method outlined in the poh, which is the same as yours. If I flood it while it's hot though, it can be a bear. To avoid that, if it has run within maybe 2 hours I'll try the hot start procedure first.

If I screw up and manage to flood it, the fix is
Mixture idle cut off
Throttle wide open
Mags on & crank
As soon as she catches, simultaneously pull throttle to idle & mixture to rich
 
ay yes, the voodoo knowledge required to start our engines

Everyone's got a different technique for this. Mine that seems to work is

-no prime
-fuel pump on
-mixture cut off
-throttle comfortably open (1/4 to half, maybe fully open depending on type.. Cirrus was fine with quarter to half, Aztec I need fully open)
-slowly advance mixture until it kicks
-adjust throttle as needed
 
tree9er said:
Long time lurker, first time poster. Might be able to help.

When starting again within 2 hours from shut-down, cowl-flaps open, and open the oil door on top of the cowl to help dissipate heat.

My hot start procedure (works for me 9/10 times):
-Do not prime
-Throttle 1/4 open
-Mixture cut off
-Mags to start
-Mixture slowly in,
-When it catches, left hand from key to fuel pump and turn on for 3-5 seconds.

Works wonderfully. Few times it does not work, I let the starter cool down for a few minutes and do the same process as above, but with throttle opened further. This has worked every time for me.
Click to expand...

Thank you! I'll give it a try
 
VictorBravo said:
I've flown a Cessna 182T for the last 4 years, primarily throughout the midwest and very often in the dead of summer. I have no concerns about hotstarts with the following procedure. BTW, this same approach works reliably with my IO-360 Husky and is my go to on any hot start, but especially on those 100 degree plus days.

- DO NOT PRIME
-Throttle set to 1,000 RPM (basically set it at shutdown and no need to worry about it on start up)
-Mixture OFF
-Crank it over until it starts...usually 3-5 rotations
-Mixture full rich immediately after it starts.

That's it, very easy and works everytime. I too went through all the complicated hot start procedures and ultimately found that there was plenty of fuel in the system and the other approaches ultimately flooded the engine with even more fuel. Hope this works for you.
Click to expand...

That procedure is the same as my Shutdown/Hot Start Procedure #2 unless I am missing something. I only have about a 50% start chance with that one.
 
Thanks for the feedback gentlemen. I should have added to the original post that I usually only have problems with really hot starts. I always do the cowl flap & oil door trick mentioned above and it will start right back up if is longer then say 45 minutes (9/10). The problem is when I drop off a passenger or just need to run in the FBO quick. Sub 10 minutes from shutdown I'm like (5/10) with the POH method.
 
Out of curiosity, what's the outside air temperature? Does it make a difference?
The 95hp Cub, when it is parked on a hot day, will percolate the fuel in the lines and flood the engine after you shut it down.
While I'm still taxiing I have to shut the fuel off and let the plane coast to a stop.
Then, usually, I can prop it with the throttle cracked, fuel off, no prime. When it starts, I turn the fuel on.
But, I usually always prop the plane with the fuel off, to limit the damage in case of a runaway.
 
Par129 said:
a Cessna 182S with a Lycoming IO-540
Click to expand...
I also fly a 182S with that same engine on occasion. My hot start procedure on that plane starts at the shutdown:

Shutdown:
  1. Throttle to 1000RPM
  2. Mixture to idle cutoff
  3. Don't touch throttle and mixture
Hot start:
  1. Don't touch throttle and mixture
  2. Key to start position
  3. When engine fires, mixture to full rich
 
Shepherd said:
Out of curiosity, what's the outside air temperature? Does it make a difference?
The 95hp Cub, when it is parked on a hot day, will percolate the fuel in the lines and flood the engine after you shut it down.
While I'm still taxiing I have to shut the fuel off and let the plane coast to a stop.
Then, usually, I can prop it with the throttle cracked, fuel off, no prime. When it starts, I turn the fuel on.
But, I usually always prop the plane with the fuel off, to limit the damage in case of a runaway.
Click to expand...
Outside temp doesn't seem to be a factor as we are talking about a quick restart. I've seen people in old cubs come coasting in with the engine off. I always just thought they were showing off.
 
asicer said:
I also fly a 182S with that same engine on occasion. My hot start procedure on that plane starts at the shutdown:

Shutdown:
  1. Throttle to 1000RPM
  2. Mixture to idle cutoff
  3. Don't touch throttle and mixture
Hot start:
  1. Don't touch throttle and mixture
  2. Key to start position
  3. When engine fires, mixture to full rich
Click to expand...
Thank you. This is my current Hot Start Procedure #2 and one everyone recommends. I just don't have the success everyone else seems to have with it. Do you pull your mixture to idle cutoff in one smooth motion say 1-2 seconds? How about restarting are you fast with advancing the mixture once it fires or slowly go to full mixture? Do you have any type of pre-hot start prayers or rituals you can share? At this point I am willing to try anything...
 
Tantalum said:
ay yes, the voodoo knowledge required to start our engines

Everyone's got a different technique for this. Mine that seems to work is

-no prime
-fuel pump on
-mixture cut off
-throttle comfortably open (1/4 to half, maybe fully open depending on type.. Cirrus was fine with quarter to half, Aztec I need fully open)
-slowly advance mixture until it kicks
-adjust throttle as needed
Click to expand...
This is basically what I follow (and where I have most success) across Conti & Lyc of various displacements. Each time this topic comes up, I’ll try out everyone else’s methods to see if I can improve. My observation is that [for me] POH’s never advise enough throttle or too much mixture.
 
kaiser said:
POH’s never advise enough throttle or too much mixture
Click to expand...
Exactly!

Par129 said:
Why is this?
Click to expand...
Because the engine in your truck isn't using 1930s technology. It was developed by a team of engineers with limitless financial capital behind them who manufacture and collect data across millions of engines built, so it's easy to refine over the years. FWIW, the FADEC airplane engines also start right up with the press of a button without having to play chemist.

Our engines are relatively simple mechanical beasts largely unchanged from the 1930s engines they were based on when most of the plane engines were developed in the 1940s and 1950, the "FADEC" is you, the operator. Beyond the reasons of "why" (costs, certification, low volume, works well enough.. Paul B recently did a cool video onthis) there can be arguments for why "less is more" in an airplane engine

I personally find it an offensive travesty, but I've stopped milking that dead horse here. Our plane engines actually aren't that hard to operate, but unfortunately you have to either a very good CFI or be inherently "bright" when it comes to mechanical things and understanding what the mixture, throttle, etc., all do in your engine.
 
If all else fails - mixture cutoff, run prime for 30 seconds to get hot vapor/fuel back to the tank and cool fuel ready to distribute, then shut off pump, go rich, and crank.
 
Tantalum said:
Our plane engines actually aren't that hard to operate, but unfortunately you have to either a very good CFI or be inherently "bright" when it comes to mechanical things and understanding what the mixture, throttle, etc., all do in your engine.
Click to expand...
I agree 100% with everything you said. Maybe someday... I'm just looking for that perfect hot start procedure that works every time. Looks like my best bet is to keep using my Shutdown/Hot Start Procedure #2 and when/if that fails go to this method. Thanks for all the help

Hot Start:
1) Fuel pump ON
2) Throttle forward. Mixture forward 3-5 seconds, flood the engine a bit.
3) Mixture idle cut-off
4) Crank until it starts. When it starts, use your 3 hand maneuver to push the mixture forward and pull the throttle back. Works really well once you get the hang of it.
 
455 Bravo Uniform said:
If all else fails - mixture cutoff, run prime for 30 seconds to get hot vapor/fuel back to the tank and cool fuel ready to distribute, then shut off pump, go rich, and crank.
Click to expand...
Not on a lyco.... no fuel return. If you're priming it, you're dumping gas into the engine.
 
Jim K said:
Not on a lyco.... no fuel return. If you're priming it, you're dumping gas into the engine.
Click to expand...

That is not an absolute. Some Lycomings return fuel. It is important to know what the fuel system is like on the specific airplane in question.
 
Par129 said:
That procedure is the same as my Shutdown/Hot Start Procedure #2 unless I am missing something. I only have about a 50% start chance with that one.
Click to expand...


My success rate is nearly 100%. The only other thing I can think of is that I aggressively lean mixture on taxi, (too the point that a quick stab of the throttle makes it stumble) perhaps that adds an element to my success rate as the amount of fuel in the system is already as low as possible at shutdown? On shutdown it's a quick pull of the mixture to off and then on start up I am mixture rich, quickly, as soon as it fires its first hit.
 
Par129 said:
Thank you. This is my current Hot Start Procedure #2 and one everyone recommends. I just don't have the success everyone else seems to have with it. Do you pull your mixture to idle cutoff in one smooth motion say 1-2 seconds? How about restarting are you fast with advancing the mixture once it fires or slowly go to full mixture? Do you have any type of pre-hot start prayers or rituals you can share? At this point I am willing to try anything...
Click to expand...
I just yank the mixture to idle cutoff. Upon restart, I let it fire and then smoothly advance to full mixture. Remember that if mixture is at cutoff and you're cranking and it takes a while to fire then that means the engine is going from overly rich towards near stoichiometric. If it fires and then dies as you continue to crank then it went from stoichiometric towards overly lean. If it's firing then it's your job to keep it near stoichiometric with the mixture knob. If it never fired, then it was probably never overly rich and you should somehow add fuel as needed, possibly using the mixture knob and/or the electric fuel pump. The few times that my hot start procedure didn't work, that little bit of extra fuel took care of it.

One shouldn't run the starter for more than 10 seconds at a time, so one needs to not delay in deciding the state of the mixture.

VictorBravo said:
The only other thing I can think of is that I aggressively lean mixture on taxi
Click to expand...

Me too. Didn't think of that as a factor. Maybe it is, maybe it isn't.
 
On my arrow, I tried the don't touch anything method at first and if it went 4 blades or so without catching, I would slowly open the throttle until it started coughing. Basically assumed it was a rich mixture and tried to find the right air ratio to make it catch. Seemed to work for me.
 
If it makes you feel any better, my 205’s IO-470 is a bastard to hot start, especially when it’s hot outside. It can really make me sweat bullets, especially when a long ways away from civilization.

My best advice: have a good battery and replace it often!!
 
I have an IO-540 in my Lance and here's what I do for hot starts, never failed to get it started.

Throttle cracked, mixture full rich.
turn fuel pump on, then off after 2-3 seconds of flow.
mixture about halfway between cutoff and rich.
attempt a start, if it catches go full rich. this part works maybe 1/4 of the time

assuming no start, basically do a flooded start. mixture to idle, throttle wide open, crank. When it fires quickly full rich and throttle to idle.

It's not elegant but as I said I always get it started.
 
cowman said:
I have an IO-540 in my Lance and here's what I do for hot starts, never failed to get it started.

Throttle cracked, mixture full rich.
turn fuel pump on, then off after 2-3 seconds of flow.
mixture about halfway between cutoff and rich.
attempt a start, if it catches go full rich. this part works maybe 1/4 of the time

assuming no start, basically do a flooded start. mixture to idle, throttle wide open, crank. When it fires quickly full rich and throttle to idle.

It's not elegant but as I said I always get it started.
Click to expand...

You might as well skip the first bit and just go flooded start from the beginning.
I do the hands off method, works 99% of the time. Takes about 12-15 blades.
 
you need a pre-start ritual:

  • draw a six-pointed pentagram on the glare shield
  • hang garlic from the whiskey compass
  • drink a cup of blood from a three-legged virgin goat
  • draw a fuel injector nozzle using phillips xc oil on your forehead (what else is that oil good for, anyways?)
  • and whatever you do, don't steal Jobu's rum. it's very bad to steal Jobu's rum
  • then:
upload_2021-7-6_9-36-52.png
 
eman1200 said:
you need a pre-start ritual:

  • draw a six-pointed pentagram on the glare shield
  • hang garlic from the whiskey compass
  • drink a cup of blood from a three-legged virgin goat
  • draw a fuel injector nozzle using phillips xc oil on your forehead (what else is that oil good for, anyways?)
  • and whatever you do, don't steal Jobu's rum. it's very bad to steal Jobu's rum
  • then:
View attachment 98003
Click to expand...

"Hats for bats. Keep bats warm." - P. Cerrano
 
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