How do I warm start an IO-360?

FORANE

FORANE

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On my new Lancair is a beautiful io-360. It has ram air, cold air intake, bendix fuel injection, one e-mag and one lightspeed ignition. I have figured out how to cold start it and hot start it. I have not figured out how to start it after a short taxi to fuel.

For a cold start, my procedure is: master on, mixture in full, throttle in about 1/4 inch, fuel boost pump on for about 5 seconds so fuel pressure gauge raises from zero to approaching the bottom of the green zone, boost pump off, key to start and slightly more throttle when it fires. This procedure works well.

For a hot start after flying for an hour or two and subsequently fueling in order to taxi to hangar:
my procedure is: master on, mixture out full, throttle in about 1/4 inch, fuel boost pump off, key to start and mixture in when it fires. This procedure works well.

For a warm start such as with a cold motor only run long enough to taxi to the fuel farm, I have trouble starting.

Any suggestions?
 
It may not help you, but I usually fill up on taxi out, engine isn’t hot. I fill then go flying, if not cross country I go to the hangar after landing.

A start while up to full temp can be a challenge. When hot I leave it at cut-off then throttle cracked, no prime.
 
sourdough44 said:
It may not help you, but I usually fill up on taxi out, engine isn’t hot. I fill then go flying, if not cross country I go to the hangar after landing.
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If I'm reading this correctly, I did not make myself clear. "fill up on taxi out, engine isn’t hot. I fill then go flying" is precisely when I have trouble starting; it's the start after the fueling on taxi out that I have trouble starting.
sourdough44 said:
A start while up to full temp can be a challenge. When hot I leave it at cut-off then throttle cracked, no prime.
Click to expand...
I'm using this same technique and have no trouble starting hot.
 
On my IO-360 I use the same procedures you're using and they typically work well (except for really warm days where hot starts after flying for a while can still be a PITA).
The only thing I'll add is I lean aggressively immediately after start-up (whether I'm headed to the self-serve pumps first or not). Same thing for right after landing. Once I'm on the taxiway I'm leaned. When I shut down I barely have to pull the lever to kill it.
I used to not do that and hot-starting was much more difficult. Can't say for certain if it's a direct cause/effect, but it certainly seemed related. Might be worth giving it a shot if you're not already.

EDIT: I didn't clarify but in your situation I would be using the same hot start procedure after you taxi to the fuel pumps. Works well.
 
Try this: Before turning on battery power, slowly/smoothly move the throttle and mixture to full forward/rich. Finish your pre engine start check list, then when you're ready, move throttle and mixture to idle/mixture-cutoff. Then proceed with your hot start method.

I don't know why it works. But it has worked for me on several 180hp IO360 powered aircraft.
 
Either completely flood it and perform a flooded start, or completely dry it out and start from lean. When you're in-between, you don't know if you're working from a rich or lean condition, which means your probability of success is 50%.
 
kyleb said:
Either completely flood it and perform a flooded start, or completely dry it out and start from lean. When you're in-between, you don't know if you're working from a rich or lean condition, which means your probability of success is 50%.
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I was gonna say my hot start is mixture ico, full throttle, although I wouldn't say I "completely flood it". it just works. actually as I'm cranking I slowly bring the throttle back and it almost always fires up when the throttle is about half way, maybe just under. I would treat his "warm start" as a hot start.
 
Warm starts with my IO-360 are different than hot starts as significant cranking is not necessary. In your example of hangar (cold start) and taxi to the fuel pump, try this procedure:

1/2” throttle. Mixture lean. Crank for 5 or 6 seconds. If no start, or at least a solid pop pop almost running result, then:
1/2” throttle. Full Rich and dump in just 1 or 2 seconds worth of boost. Lean then crank again.
If that doesn’t work, you’re on your own!


Slightly off topic, but I find very hot starts are better handled differently than the POH recommends, as follows:

1/2” throttle. Mixture lean. Crank (sometimes a lot - maybe 10 to 12 seconds) until it kind of starts roughly, go full rich and IMMEDIATELY hit the booster pump on for 2 or 3 seconds as it’s stumbling. It should smooth out, running with varying RPM for a short period of time as the very hot “spider” fuel lines on top of the cylinders purge whatever fuel vapor remains up top.
 
eman1200 said:
maybe touch nothing and just crank.
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This works for me. I also make sure to set the throttle for 1000RPM at shutdown.

But this is with parallel valve Lycomings. I only have a few hours in an angle valve Lycoming IO-360 and haven't gotten around to the Continental IO-360 yet.
 
asicer said:
This works for me.

But this is with parallel valve Lycomings. I only have a few hours in an angle valve Lycoming IO-360 and haven't gotten around to the Continental IO-360 yet.
Click to expand...

Oh sht I guess I assumed lyco.
 
Old redneck buddy of mine told me the SUREFIRE way to get skunk smell off a trap…

3 to 4 weeks…

I hot start Conty io-360s by waiting for them to get cold.
 
Sierra_Hotel said:
But how do I crank it without touching it? Instructions unclear.
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Shutdown: Set it for 1000RPM and pull the mixture all the way out. After the prop stops, turn off the master.

Restart: Turn on the master and just crank. Touch nothing else. When the engine fires, smoothly advance the mixture to keep it running.
 
ok, to clarify, it's a ly-con built Lycoming io-360A1A 200 hp engine.
Thanks for the replies; I will give em a try.
 
wilkersk said:
Try this: Before turning on battery power, slowly/smoothly move the throttle and mixture to full forward/rich. Finish your pre engine start check list, then when you're ready, move throttle and mixture to idle/mixture-cutoff. Then proceed with your hot start method.

I don't know why it works. But it has worked for me on several 180hp IO360 powered aircraft.
Click to expand...

When you do that you will see the fuel pressure drop to 0, so you’ll have cool fresh fuel in the lines, can make starts a little smoother.
During summer temperatures anything you can do to cool engine will help; open cowl flaps on approach, park with nose into the wind.
 
I learned to fly during the hot summer days in a 172S.
Everyone at the school had trouble starting them hot, even the owner of the flight school. I watched the owner come out one time and crank it for 90 seconds or something like that and a big puff of black smoke came out when he finally got it started.

We were only allowed to crank it for 20 seconds and then had to wait 2 minutes for the starter to cool down. When it is 95° out that 2 minutes felt like an hour.
I hated that during the summer. Every flight instructor would instruct you to prime it differently.
 
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FORANE said:
On my new Lancair is a beautiful io-360. It has ram air, cold air intake, bendix fuel injection, one e-mag and one lightspeed ignition. I have figured out how to cold start it and hot start it. I have not figured out how to start it after a short taxi to fuel.

For a cold start, my procedure is: master on, mixture in full, throttle in about 1/4 inch, fuel boost pump on for about 5 seconds so fuel pressure gauge raises from zero to approaching the bottom of the green zone, boost pump off, key to start and slightly more throttle when it fires. This procedure works well.

For a hot start after flying for an hour or two and subsequently fueling in order to taxi to hangar:
my procedure is: master on, mixture out full, throttle in about 1/4 inch, fuel boost pump off, key to start and mixture in when it fires. This procedure works well.

For a warm start such as with a cold motor only run long enough to taxi to the fuel farm, I have trouble starting.

Any suggestions?
Click to expand...
Try turning your fuel valve to off as you shut down. Turn it back on when ready to start.

You should add another Pmag. With my IO-390 I start it hot just like when cold, but the priming time is shorter. Fires up every time.
 
When I bought my Arrow, the first flight I took was from the prebuy shop to the owner's field to sign the paperwork. Quick 10 minute flight over Pheonix. Imagine my horror when, right after signing for the biggest purchase of my life, I couldn't get the thing to start!

IO-360 warm starts suck. Eventually I started making sure to run the pump for a little bit (while at idle cutoff) to clear out vapor lock.

Now I have a Surefly and the thing seems to start like a car on the second turn no matter what. Only exception was when my battery was bad recently and the starting current browned out the surefly. Highly recommend.
 
There is a range of ratios at which a mixture of air and fuel will ignite. Too rich or too lean = no fire.

If you try to prime to the correct ratio, but it fails to fire, you don't know whether it was too rich or too lean to start.

So the better strategy, and the one endorsed by Lycoming, is to prime it too rich, and drag it through the range by cranking with the mixture closed. The airflow will suck the fuel vapor out and lean the mixture as it cranks. If it starts rich, it has to pass through the ignition range, where it will fire with spark.

In your situation, I would try the method Asicer suggests. The cylinders will have fuel in them from shutdown. So just crank it and see if it fires. If that doesn't work in a few seconds, give it a 1-2 second shot of prime and try again.

My personal opinion is the process works better with the throttle open 1 to 2 inches.

I prime by closing the mixture and throttle, running the pump until pressure is green, then opening the mixture for the desired prime duration. Every time a cold start has failed on me, it was due to too short a prime, not too long, IMO.
 
Stewartb said:
Try turning your fuel valve to off as you shut down. Turn it back on when ready to start.

You should add another Pmag. With my IO-390 I start it hot just like when cold, but the priming time is shorter. Fires up every time.
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Adding another p-mag would be easy as I have 2 spares sitting on the shelf at home. I like them and may do just that for a couple reasons. But, the Lightspeed has impressed me so far. On mag checks with the p-mag alone I get a large drop of maybe 100; on the LS alone I get close to zero drop. It seems to run smoother on the LS alone.
 
FORANE said:
throttle in about 1/4 inch, fuel boost pump off, key to start and mixture in when it fires
Click to expand...
This is basically the just turn the key procedure others have mentioned and works well in the Mooney I occasionally fly.
I do find that for hot starts often 1" or a bit more throttle seems to work better. It is likely already rich so adding a bit more air helps it start and keep running until the mixture stabilizes.

if it doesn't act like it is going to start after a few seconds of cranking is would consider to try turning on the fuel pump and then advancing the mixture while continuing to crank.

Brian
 
When I had my Arrow with an IO-360, I followed the previous owner's procedures for warm and hot start and they always gave me trouble. I found the key to reliable warm and hot starts was making sure I was adequately leaned coming into shut down. Meaning, make sure when you're taxiing to fuel that you're leaned maximum. Startup for both warm and hot is just battery, anti-col, throttle slight (maybe 1/10), mix cut, start and slowly advance mixture as engine starts to fire.
 
Push the throttle from idle to full forward then pull back to full idle.
Whatever that range is push the throttle to around 1/3 of the way open.
Start cranking with the throttle in that position and mixture cut off.
After 2-3 blade rotations push the mixture forward at a rate that would take around 3 seconds to go from full cut off to full rich.

As soon as it pops off be pulling back on the throttle a bit.

Check your key switch innards to verify you are not trying to start it on only 1 mag.
 
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FORANE said:
Adding another p-mag would be easy as I have 2 spares sitting on the shelf at home. I like them and may do just that for a couple reasons. But, the Lightspeed has impressed me so far. On mag checks with the p-mag alone I get a large drop of maybe 100; on the LS alone I get close to zero drop. It seems to run smoother on the LS alone.
Click to expand...
Interesting. There must be a timing or timing curve difference between them. I wouldn’t mix two electronic ignitions. My own Pmags are retarded a few degrees to assure safe starting. With yours you’d need to set the Pmag timing to closely match the LS. I have no idea what the LS advance map looks like.
 
Eric Pauley said:
Eventually I started making sure to run the pump for a little bit (while at idle cutoff) to clear out vapor lock.
Click to expand...

Different engine, but I can get my IO-470 started this way, about 30 seconds worth. Before cranking I then go full rich.

Then advance throttle slowly as I crank to get the right amount of air to fire. (Imagine how hard a hot engine would be to start if you had the choke closed…in the olden days or with a lawn mower; same concept).
 
I believe his is a Bendix with a header tank. As long as there is pressure from the boost pump, but no flow to the engine due to mixture cutoff, the hot vapor/fuel returns to the header??
 
455 Bravo Uniform said:
I believe his is a Bendix with a header tank. As long as there is pressure from the boost pump, but no flow to the engine due to mixture cutoff, the hot vapor/fuel returns to the header??
Click to expand...
Yes, correct on all.
 
The plane has been down for maintenance for a month or two. Finally got back to flying it today. I was successful at warm starting it by following some of the suggestions offered here. I set throttle at about 1/3 in, mixture at idle cutoff, turned on the boost pump, immediately started cranking and advancing the mixture. It started right away. Thanks for the suggestions.
 
Most reliable hot start method:
1) Ask everyone on PoA
2) Read the eleventy-thousand opinions that people post for entertainment purposes.
3) Ask @Ted and just do what he says.
 
Eric Pauley said:
When I bought my Arrow, the first flight I took was from the prebuy shop to the owner's field to sign the paperwork. Quick 10 minute flight over Pheonix. Imagine my horror when, right after signing for the biggest purchase of my life, I couldn't get the thing to start!

IO-360 warm starts suck. Eventually I started making sure to run the pump for a little bit (while at idle cutoff) to clear out vapor lock.

Now I have a Surefly and the thing seems to start like a car on the second turn no matter what. Only exception was when my battery was bad recently and the starting current browned out the surefly. Highly recommend.
Click to expand...
I had the same problem with my mooney. Vapor lock. Just have to wait for the engine to cool down.
 
455 Bravo Uniform said:
I believe his is a Bendix with a header tank. As long as there is pressure from the boost pump, but no flow to the engine due to mixture cutoff, the hot vapor/fuel returns to the header??
Click to expand...
Bendix with a return line? Do you mean a purge valve? Bendix doesn’t use a fuel return to an accumulator like Continental does. Some guys do add purge valves, but most don’t.
 
Stewartb said:
Bendix with a return line? Do you mean a purge valve? Bendix doesn’t use a fuel return to an accumulator like Continental does. Some guys do add purge valves, but most don’t.
Click to expand...
Yeah mine lacks a return line; also lacks a purge valve. Since this thread was started it also lacks a Bendix mag. I'm now running a lightspeed plasma 3 and an e-mag.

Regarding the subject of the thread , I've figured out how to warm start it. I still do as I indicated in the first post but the throttle is set for 1/3 to 1/2 way in rather than the small amount I indicated previously.
 
My IO-390 starts the same hot or cold. Prime it, crank it, let the electronic mag’s hot spark light it. Flooding is a non-issue. I never had problems with Continental injection and Slick mags, either. ‍♂️
 
Mine doesn't have a primer. I've been injector nozzle tuning recently. That doesn't seem to have affected the starting at all. Regardless it starts quite well now that I've figured out how to do it.
 
FORANE said:
Regarding the subject of the thread , I've figured out how to warm start it. I still do as I indicated in the first post but the throttle is set for 1/3 to 1/2 way in rather than the small amount I indicated previously.
Click to expand...

This is the key. Half open throttle drags air through the cylinders, moving them from too rich to too lean. The mixture MUST pass through the ignition range, so it fires. As long as you don't re-flood them by prematurely opening the mixture, you should get it running. I find it works best to let it fire, then start to die before opening the mixture. If that fails, prime it for 1 second and try again with same method. I just went on a 3 week trip with dozens of hot starts, and the only time I had a problem was when I opened the mixture too early.
 
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