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RV8 IO360 hot start problem

TheBelle

I'm New Here
I’m having a very difficult time starting my plane when the engine is hot. The engine starts beautifully when cold but after a flight and when I go to restart the engine it is very very difficult to get it to start back up. The engine is a fuel injected I0360. The fuel distribution manifold also known as the spider is situated on top of the engine. I feel that the fuel is vaporizing due to the heat buildup underneath the cowling which is causing the problem. Has anybody had any experience with this? What was your solution? Thanks.
 
I have an I0-360. For hot start I turn on boost pump with mixture at idle cut-off to pressurize fuel lines for a second. Open throttle about 1/4th and crank, mixture full rich when it fires. If it doesn't catch the first time I prime it for about a second and try again.
 
I have used a variation of @swjohnsey 's method for both IO360 and Continental IO470.

As soon as you get in the airplane, before doing anything else, push throttle and mixture to full open and leave them there for a about 10 seconds, then close both. Next, proceed as in swjohnsey's post above.
 
I had the same problem. I got told to open the throttle full, mixture closed, and then start to feed in the mixture til it fires, AND pull the throttle back very quickly. I didn't like the throttle wide open trick, so I just put it to half way. It always takes me twice, but on the 2ed attempt, it always starts. Once in a great while, if the 2ed attempt doesn't work, I'll flip on the boost pump for maybe a second and 1/2. Then it always starts, but I rarely have to go for this 3rd attempt. The 2ed attempt almost always works.:cool: And oh yeah, even at half throttle, yank it back to idle when your engine fires.
 
My IO-360 hot start procedure (in the Mooney) is:

Mixture idle cutoff
Open throttle 100% for approx 30 seconds, then approx 1/2" open
Crank until firing (usually takes less than 4-6 revs), smoothly advance mixture
Adjust throttle

I had a terrible time learning hot starts until my Mooney transition instructor gave me this procedure. Now it works almost every time on the first try, if not, second try gets it. I never use the boost pump for hot starts.

I hope this may translate to injected RVs in general.
 
Hot Start

I've been successfully starting the Doll's hot I0360A1B6 for 20 years. I never have a problem with hot starts. Each pilot develops his/her own technique. Some errors are learned from flight instructors that haven't a clue how to do it.
Try this: After you follow the Shutdown procedure, don't change a thing other than cracking the throttle. Your engine is already rich from boiling off the fuel in the spider lines into the cylinders.

Shutdown
1) Mixture off
2) Battery off
3) Ignition off

Hot Start
1) Battery on
2) Ignition on
3) Throttle crack
4) Starter engage
5) After start mixture rich

Do Not turn on boost pump!
Do Not advance mixture until engine start!
 
I've been successfully starting the Doll's hot I0360A1B6 for 20 years. I never have a problem with hot starts. Each pilot develops his/her own technique. Some errors are learned from flight instructors that haven't a clue how to do it.
Try this: After you follow the Shutdown procedure, don't change a thing other than cracking the throttle. Your engine is already rich from boiling off the fuel in the spider lines into the cylinders.

Shutdown
1) Mixture off
2) Battery off
3) Ignition off

Hot Start
1) Battery on
2) Ignition on
3) Throttle crack
4) Starter engage
5) After start mixture rich

Do Not turn on boost pump!
Do Not advance mixture until engine start!

+ 1. This has worked for me with every bendix injected Lycoming I have started warm or hot.
 
My method is to turn off the fuel to kill the engine. Let the engine burn what's left in the lines. No fuel, no vapor lock. Normal start when you are ready.
 
I’m having a very difficult time starting my plane when the engine is hot. The engine starts beautifully when cold but after a flight and when I go to restart the engine it is very very difficult to get it to start back up. The engine is a fuel injected I0360. The fuel distribution manifold also known as the spider is situated on top of the engine. I feel that the fuel is vaporizing due to the heat buildup underneath the cowling which is causing the problem. Has anybody had any experience with this? What was your solution? Thanks.

Please post more details of your engine and starting issues:

1. How much time is on the engine.
2. Have you always had this problem or is it new (or is it a new plane)?
3. What type of ignition do you have
4. When you are having trouble with hot starts, is it after 5 minutes of shutdown, 30 minutes, 1hr or ???
5. What brand and model fuel injection system is installed?

FWIW, I have about 1000 hours on my RV-8 (I'm the original owner and builder) that is equipped with a stock I0-360A1B6 and Slick magnetos. I have never had hot-start issues accept for a brief spell earlier this year. I discovered that I potentially had a bad intake gasket which I replaced. The problem seemed to subside and returned ~ 1 month later. I then discovered that the intake tube to sump O-Ring had been pinched/dislodged and sucked inward a bit. The engine started fine cold but I had a lot of trouble when restarting after a fuel stop. Once the gasket was found and replaced I no longer have any hot start issues.

Skylor
 
I've been successfully starting the Doll's hot I0360A1B6 for 20 years. I never have a problem with hot starts. Each pilot develops his/her own technique. Some errors are learned from flight instructors that haven't a clue how to do it.
Try this: After you follow the Shutdown procedure, don't change a thing other than cracking the throttle. Your engine is already rich from boiling off the fuel in the spider lines into the cylinders.

Shutdown
1) Mixture off
2) Battery off
3) Ignition off

Hot Start
1) Battery on
2) Ignition on
3) Throttle crack
4) Starter engage
5) After start mixture rich

Do Not turn on boost pump!
Do Not advance mixture until engine start!

Works for me every time!
 
Same procedure I use on a IO 540 with mags that works great. I wondered his starting procedures because I had a friend who used the same method hot or cold and had a terrible time with hot starts.
G
 
I was having the same problem, cold and hot starts, and the situation continued to deteriorate over the last few hours. I sent the mags in for inspection even though they had low time and they were off by more than 20° internal timing!
Problem fixed !
 
A cranking engine will fire only when the in-cylinder fuel-air ratio is within a narrow range. It's near impossible to figure out a perfect "sweet spot" control setting for all conditions and all airplanes.

So, a successful start procedure finds the sweet spot by sweeping fuel-air ratio through a range of mixtures while cranking, moving either from rich to lean, or from lean to rich. At some point in the sweep, one or more cylinders pass through the sweet spot, and it fires.

Think about how to sweep the mixture, experiment with the knobs a bit to accomplish a sweep, and you'll arrive at procedure that works for you.
 
Lycoming Hot Start Recommendations (unofficial)

i-hMgZvX2-M.jpg


Seems a thread like this appears monthly and I post this image as a public service at every one I see....

Taken at OSH during a Lycoming seminar....a few years back. 'Scuse the noggin in the picture.

Procedure works.

I'm a "full throttle" guy instead of "set for fast idle" type per the slide to reduce cranking time.

I've practiced full throttle starts enough now over the last ~500+ hours to easily manage that process so that when the engine just starts to hit its sweet spot and fires off, I can back off the throttle position enough to prevent a runaway and the dexterity required in swapping the mixture control/throttle positions enough to keep things running is second nature now.

Good luck with it.
 
Thanks very much for all the great replies. I am eager to go and try out everything I’ve learned. I’ll let you know how I go on.
 
I have a stock Lycoming IO-360-M1B, two mags, sky-tec NL starter, Avstar fuel injection, stock Airflow Performance fuel pump, snorkel built to plans, and the fuel flow cube inline between the engine driven pump to FI servo that adds no additional hose length- it was a steep learning curve to repeatedly successful hot starts. I tried everything people talked about on VansAirforce; you name it, I tried it. Then it finally got dialed in- throttle open to ~1200-1500 RPM, mixture off, fuel pump on, after starting, wait briefly, then slowly advance mixture; too much mixture too soon, overwhelms the fuel/air mixture. In combing through google searches, I had discovered advice that the engine driven pumps do not deliver enough flow at low RPMs, during hot start, to keep the engine running. In any advent, each of our planes is a unique setup, and you will need to discover what combination works for you. It's part of the fun of building and flying a homebuilt. Good luck, and have fun!
 
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Likewise, I keep the boost pump on during a hot start (and cold). Throttle cracked. No prime. Slow advance on mixture from ICO until it fires. Works for me. Precision Airmotive Silverhawk Servo. No return to tank.
 
Update re hot start problems.....

Checked plug resistance and 4 of the 8 plugs were bad. Two had 1,000,000 ohms and two were open circuit!!! Changed all 8 plugs. Then used the Dolls hot start procedure. Seems to have solved the problem. Thanks.
 
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