Continental IO-360 Hot Start/idiling questions/advice neede!

[M4Mauleman]

Hello I just purchased an M4 210 on Edo 2440's, The motor has about 25 hours on it. First problem is I can not get it to idle down lower than 800rpms or it will die, is this common rpm range? Any suggestions? When it dies or even when I need to shut down for only a few minutes it is very difficult to get running again. This is what I've seem to have figured out so far. Full throttle, full lean mixture, crank until it fires and add mixture and throttle back, sometimes it catches and stays running, when it doesn't run sometimes I add a couple of seconds of boost pump after throttling back while its coughing and sputtering. This is my first Continetal motor and first fuel injected motor. Any hot start suggestions.
Thanks

[taildragger]

I have an M5 with the IO-360. I generally idle at 1000 rpm on the ground but it does not die at 800. Don't have any good advice except clean the injector nozzles and make sure plugs are clean and gapped.

Hot starts, or even remotely warm for that matter. I use full lean mixture, full throttle, turn electric boost pump on and just be patient. Wait around 15 to 20 seconds. Usually I watch the fuel pressure gauge until it just barely flickers, at that instant I go full rich mixture and turn the boost pump off at the same time. Pull the throttle to full idle then just crack it and crank er up. If it does'nt fire up almost immediately then I'll give it a quick pump of throttle while I'm still cranking. Works every time. I've been flying behind it a couple years now and have found it to be trouble free and a good running motor. Let it warm up good before take off. (Usually around 5 minutes) Gradual power reductions coming in to land so as not to shock cool and I think you will be happy with it.

Scott

[M4Mauleman]

Thanks for the reply I will try your starting procedure. I would like to idle down below 800rpm because coming into a dock (when on floats) while idling above 800rpm's is to fast and scary. I am used to the carbed Lycomings that I'v had were you can idle at 500rpm then go to one mag and drop down to 425. Is that possible in the injected continental? I have new plugs and New Gami Injectors.

[210TC]

Contact the engine builder, it sound like a vacum leak. If it's not a vacum leak it steal needs to be fixed. With only 25 hours it should be covered.

[MikeW]

Mauleman,

I have an M4-210. You may want to have your mechanics check your mixture adjustment screw which is right up front on top of the motor. It sounds like your running a little lean. My engine will run at idle at about 5-600rpms with throttle closed. During your runup see if you get a noticible rise in rpm when you lean out your mixture, if it just starts to run rough and then quit your running lean.

Starting cold: Throttle and mixture both in, boost pumpt on(ensure your getting good pressure on your gauge) for 5-10 seconds, pump off, throttle back to almost closed and hit starter.

Start hot: Throttle and mixture both in, hit pump just enough for fuel pressure to peak on your gauge and then pump off throttle back and hit starter. The pump is being used to clear fuel vapor out of the injection lines

I have used this start procedure and have had no problems

Mike

[M4Mauleman]

What is a good number to see for boost pressure? The shop that built the motor is about 400 miles away. The mechanic thats worked on this bird seems to think that it is normal and I have to figure out the quirks for this particular motor, he has other customers that have quirks or starting procudures for each different plane.???? I will try Sunday morning....

[210TC]

I would be VERY concerned if the engine builder was not concerned.
I agree with the engine starting procedure. However, IF the engine is running lean it could cause damage to the pistons and cyl's.
Please get this checked out by a professional.
As MikeW stated, when your at idle if the engine rpm rises while pulling the mixture out slowly it is not running lean. Do this check to make sure.
It is possible to get an rpm rise and still have one lean cylinder.
This idle problem could be many other things. I just don't want to see anyone damage their engine.

[M4Mauleman]

I cured the idle problem, to idle back to the throttle stop we needed to add some fuel, very small adjustment though. It idles at about 650 now on the water. The mixture needs to be leaned slightly starting about 800 rpms. Thanks MikeW and 210tc. The starting combinations I have tried. Seems I am giving up to soon(I think). I am going to try cranking 5-7 blades next time? What fuel pressure are you running not started, with and without boost? and at idle without boost? How long due you crank hot?

[MikeW]

I don't look at the fuel flow gauge very much anymore during start but I think with the throttle in and boost pump on I get about 6.0 and if the throttle is closed about 3. It's a little easy to flood the motor during a cold start. If the boost pump is on for more than about 8 seconds or so you will hear fuel dripping out the bottom of your motor.(If you are on floats you might not hear this). If you flood it, or the motor is really hot you can let it sit awhile, or try doing the same start procedure for the hot start only this time leave the throttle in while you crank it and give it some good turns to clear out some of the vapor/fuel before giving up. Starting is one of the hardest things on your engine so don't get carried away with the cranking. Hope this helps

MikeW

[Walter Atkinson]

The idle mixture is set improperly. Get that adjusted and it should idle quite nicely as low as about 600 RPM. (It could also be an issue with induction leaks.)

As for Hot Starts on TCM injected engines:

The problem is simple. The engine driven fuel pump is heat soaked and is causing vaporization. Cool the engine driven fuel pump and you no longer have a hot start. To do this:

1) Idle cutoff
2) run boost pump for 60 seconds. (this runs cool fuel through the housing and cools it off.)
3) Do a normal cold start sequence.

Works every time since you have removed the issue that creattes a hot start.

This does NOT work on Lycomings.

[Maule-igan]

When you set up the motor it is required to set up the fuel injection. Metered fuel and unmetered fuel as well as idle mixture. They all work together and the plane will not run well until you do this. You can go to the TCM website and download the service letters SID97-3E. You will need to sign up. and it also requies having the correct certified gauges also.