Hot Engine Start on fuel injected engine

[Wayne]

I have a IO-360 A3B6 with a purge valve.

Getting ready for 1st flight and trying to finish off my POH. Need input from others on what the starting procedure is for a heat soaked fuel injected engine with a purge valve. I have never flown an aircraft with a purge valve and would also welcome comments on its use for engine shut downs or ???

Thanks for your help

Wayne
C-GOYA
RV 7eh?
48 hours from 1st flight!!??

[dan]

- Throttle at least 1/2 open
- Mixture full rich
- Purge valve on ICO (purging...should be there already from shutdown)
- Boost pump on
- Purge for 30 seconds (mine stabilizes around 3.8 gph)
- Boost pump off
- Ignition source(s) on (I enable both impulse-coupled mag & Plasma II)
- Engage starter
- When it catches (or just before if you can "sense" it...use the force Luke), quickly push the purge valve in (to the run position) and retard the throttle to idle.

I'm sure there are lots of other methods, but that's mine.

[dan]

Forgot to mention shutdowns with the purge valve...how about this for simple...

- Pull purge valve (to ICO setting)

That's it. You have cut fuel off from the flow divider and the engine will stop.

If you need to start the engine right away after shutting down, just push the purge valve in and click the starter. It's when the engine has had a chance to sit for a while after a hot shutdown that it makes life interesting on the restart.

[SteinAir]

No doubt you'll hear several "best methods" for hot starting an Injected Lyco, but it's been my experience over the years that no one single method works....seems nearly every Lyco has it's own personality. Plus, there isn't just "one" hot start. For me, there is at least 3...

1) Start immediatly after shutdown type hot...on a hot calm day
2) Start within 15 minutes but after 2 minutes hot..
3) Start between 15-40 minutes

Then, there's the days when the weather, winds, temperature, etc.. change everything. I find it really depends on how long my engine "soaks" after shutdown. Dan's methods are pretty spot on, but I guess I'd add that you'll just need to get a few dozen hot starts under you belt before you know how your engine behaves......

Cheers,
Stein.

[BruceMe]

I have a simple rule regarding fuel application: It's really difficult to flood a too-cold engine or starve a too-hot one.

Engines that are really bad hot starters have a scenario where some section(s) of the fuel line is somewhere that's hot enough to boil the fuel. That causes all the fuel to flow under boiling pressure into the ports. So you have two bad things happening at the same time; All your fuel is puddled (flooded) in or around the cylinders and all your supply lines are full of air (starved). Purge valves will help fix the second problem, but can't fix the first.

That said... because hot-start is like starting a pre-flooded engine, I typical give absolutely no fuel till the engine shows signs of life. Once it kicks even once, I have enough information to diagnose flooded vs. starved.

Flooded: Spell fuel? Maybe kicks once or does not kick at all. Backfire.
Starved: kicks sporadically (think Harley), then dies a slow painful death as it runs out of fuel.

Openning up the throttle can really help clear an effectively flooded engine. Mechanics HATE to hear an engine roar to life at 2,000 rpm, but sometimes on a hot-start, that's what you have to do.

My .02 of experiance, hope it helps.

-Bruce

[pierre smith]

For what it's worth, the Agtrucks we dusted in flew 14 to 20 loads a day and hot starts within ten minutes were an everyday affair. Those IO-520s liked to just have the starter engaged, with the mixture rich. We just knew that there was enough 'prime' from the heat under the hood expanding the fuel and priming the engine. As it barked to life, knowing that the revvup was short lived, we'd hit the boost pump for a few seconds to "catch it" and then it'd keep running. As the others have mentioned, these engines just really may have a mind of their own!

[f1rocket]

Here's what works for me. BTW, I have a purge valve but don't use it for hot starts.

1) Throttle full open.
2) Fuel pump for 5 seconds.
3) Mixture to full lean.
4) Engage starter.
5) Just as it catches, push mixture to rich and a tic later, pull throttle back to idle (This is a one-handed operation that I do with my thumb and little finger, just a twitch of the wrist.

Works every time. If you are a second late on the throttle, you'll have a nice little scare as the tail will come up just a tad.

[n615ks]

I'm with Randy on this one. Open throttle & closed mixture. I normally don't even hit the pump, unless some time has elapsed. Just get the mixture in pull the throttle back to limit the revs as RPM comes up. I haven't been stranded yet.

I'm sure they are all a bit different, but this is the only one I have to work with.

[markscogg]

[quote=f1rocket]Here's what works for me. BTW, I have a purge valve but don't use it for hot starts.

1) Throttle full open.
2) Fuel pump for 5 seconds.
3) Mixture to full lean.
4) Engage starter.
5) Just as it catches, push mixture to rich and a tic later, pull throttle back to idle (This is a one-handed operation that I do with my thumb and little finger, just a twitch of the wrist. [quote]



This is also my method. I run pump until gage shows 25+ psi for 1-2 seconds.
No purge valve or fuel flow on my plane.
Mark
Flying -6