Injected engine hot starts?

[rbowen]

Would you veterans share how you hot start the injected Lycoming engine (mine is an IO-540V4A5)? I recognize this likely has been discussed before, but a search didn't turn up much. I'd appreciate your input.

Thanks in advance!

[Henry L. Heaberlin]

At the risk of starting a fight I'll throw my two cents in on this subject. I was told many years ago, that the problem with a hot fuel injected Lycoming was NOT knowing the fuel state in the engine. The fuel injector spiders are mounted over the engine in the hottest part of the cowling and tend to "cook off" or vaporize the liquid fuel in the lines after shut down. Make absolutely sure that your mag or mags are in good shape as hot starts tend to task them worse. One of the newer light weight starters that turn a little faster is helpful. In order to determine what your fuel state in the injector system is, open the throttle, go full rich on the mixture, and TURN ON the boost pump. Normally you can hear the pump change note or sound when it picks up fuel and starts to pump. Pull the mixture to idle cutoff, leaving the boost pump on, throttle in some, and start cranking. Normally my bird (IO-540 W1A5D) will start fairly quickly. At this point, when the engine starts firing, come in with the mixture and retard the throttle to idle. The boost pump gets turned off last. The reasoning that makes this work is that you have a known fuel state (possibly slightly flooded) at the beginning, but with the mixture at idle cut off no fuel is flowing. When the engine starts to crank, with the throttle open and fuel off it will reach a good fuel to air ratio and start firing. Leaving the boost pump on will give the system an opportunity to catch up quickly when you come in with the mixture. This system has worked for me on many fuel injected lycomings over the years. There could be an argument that you are deliberately flooding the engine with this system, but everything in moderation. Now having said this, I will say your mileage may vary.

[a64pilot]

If you do the flooded start thing, be sure to have a fire extinguisher handy, it's possible you may need it.
Of course I think your crazy if you don't have a fire extinguisher in the airplane no matter how you start it.

[Henry L. Heaberlin]

Yes, I agree about the fire extinguisher but would go one further and say a Halon fire extinguisher to prevent the inevitable corrosion caused by a dry chemical extinguisher. I do carry a Halon on board the ship. Remember I said the "flooded" start procedure in moderation.... Not dripping on the ramp... Take care.

[iceman]

Yes, I agree about the fire extinguisher but would go one further and say a Halon fire extinguisher to prevent the inevitable corrosion caused by a dry chemical extinguisher. I do carry a Halon on board the ship. Remember I said the "flooded" start procedure in moderation.... Not dripping on the ramp... Take care.

doesn't do you any good when you fly a plane and your fire extinguisher is on your ship........

[gbarrier]

Just ran across this old thread and agree that Henry's post is right on. I spent over thirty years in the air charter business flying pipers with injected lycomings and this is the way I taught it. Just flood it, pull the mixture back, open the throttle and crank. The excess runs out of the snuffa valve in the intake and there is no fire. That happens with carburated engines. Leave the pump on so when you push the mixture up the fuel will flow. Otherwise the drop in the pressure when you open the mixture causes a temporary vapor lock and the engine may quit. Checked out a couple hundred captains many flying over a thousand hours a year and never a problem with the technique. Never a fire from it either.

[Hottshot]

The Only time I have ever used the Boost pump on the IO was for first start, on a hot start mixture full off throttle full off, hit the key and slowly feed in mixture as it starts to fire open throttle and off you go. Now if it don't fire flood it (with boost pump) and open throttle full, mixture at idle cut off and crank it till it fires and with those cat like reflexes that all pilots posess pull the throttle back and feed the mixture in to keep it fired up......

[kneel]

I hot start my like wup, except I only open my throttle about 1/4 of the way. This has always worked very well for me. So well that I have even hand propped a hot engine this way with two pulls.

[Rezrider]

I hot start my like wup, except I only open my throttle about 1/4 of the way. This has always worked very well for me. So well that I have even hand propped a hot engine this way with two pulls.

Wazzup Kneel!

[Redhawk]

I have a injected Continental IO360 in my M4. I've had trouble this summer starting again after shutting down when it's hot. I scoured the Internet for hot start techniques and found this technique:

1. Throttle and mixture full forward for about 15 to 20 seconds... (Maybe this equalizes vapor pressures in the fuel injection plumbing??)
2. Retard mixture to idle cut-off
3. Throttle set to about 1000 rpm position.
4. Boost pump on
5. Start engine and gradually feed in mixture

I'll be darned it worked!!

[Flamiel]

Super hot, medium hot, works everytime.

Prime with boost pump for a second or two. Full lean, full throttle, crank and get ready to ninja move full rich and throttle back. Never had a problem. Lycoming IO-540-W1A5.

[Jayson v Schalkwyk]

Flamiel,

I also have the W1A5D and after a few frustrating attempts I now also use your technique.

1. Mixture full rich
2. Power full forward
3. Prime for 1 or 2 seconds
4. Mixture to full lean (wind vernier out as far as it will go)
5. Crank
6. Ninja hands...
7. Once running, lean till RPM just rises

I found that trying to crank with the mixture at any position other than cutoff is futile.

I am based at a field that is 5400ft amsl.