Engine won't start after oil change

[Bob Noel]

fingers crossed

 

[bonefishpete]

Like this? Sadly didn’t go over too good.

To start a Porsche Mooney airplane, simply turn the ignition key like you would start a Porsche car; there's no need for any special "airplane" starting procedures as the engine is essentially a car engine, meaning you can just turn the key to start it,

 

[Dan Thomas]

Like this? Sadly didn’t go over too good.

To start a Porsche Mooney airplane, simply turn the ignition key like you would start a Porsche car; there's no need for any special "airplane" starting procedures as the engine is essentially a car engine, meaning you can just turn the key to start it,

And only 41 of those airplanes were built. https://en.wikipedia.org/wiki/Porsche_PFM_3200

The engine has not been available since 1991.

 

[Hang 4]

To start a Porsche Mooney airplane, simply turn the ignition key like you would start a Porsche car; there's no need for any special "airplane" starting procedures as the engine is essentially a car engine, meaning you can just turn the key to start it,

Not sure what year the Porsche Mooney was, but a pre 1984 911 could easily be as cranky as a Lycoming. I had a 1980 and starting it was always an adventure.

Glad the OP got it worked out and also good the mechanic didn't go right to the "parts cannon".

 

[TCABM]

Not sure what year the Porsche Mooney was, but a pre 1984 911 could easily be as cranky as a Lycoming. I had a 1980 and starting it was always an adventure.

Glad the OP got it worked out and also good the mechanic didn't go right to the "parts cannon".

Porsche-powered Airplane: The story of my Mooney Porsche PFM | Porsche Club of America

After hearing rumors of Porsche working on an aircraft engine, I started writing letters to Peter Schutz at Porsche and Roy Lopresti at Mooney to encourage a joint venture. Aviation engines have used the same old technology for decades, so the thought of an advanced design from Porsche using the...

www.pca.org

 

[Hang 4]

@TCABM By 87 the engines actually did start easily, thanks for the post.

 

[Dan Thomas]

Porsche-powered Airplane: The story of my Mooney Porsche PFM | Porsche Club of America

After hearing rumors of Porsche working on an aircraft engine, I started writing letters to Peter Schutz at Porsche and Roy Lopresti at Mooney to encourage a joint venture. Aviation engines have used the same old technology for decades, so the thought of an advanced design from Porsche using the...

www.pca.org

That article mentions the one huge factor in developing modern aircraft engines: Liability. It's what killed the Porsche engine. The fear of being sued. The same factor that caused Cessna to shut down singles production in 1986 until tort reform ten years later. Liability is still a big factor, and is the main reason why airplanes and engines are so expensive and why advances are mostly avoided. More complex stuff has more failure modes, and since some failures now are due to a lack of proper maintenance, why would a manufacturer make the improvements when the cost is so high, the liability is so great, and the market is so small?

 

[flyingcheesehead]

In full open you are providing lots of air to the engine.

As you close the throttle you are reducing airflow and effectively

leaning the mixture.

If you're reducing airflow, you are enrichening the mixture. Reducing fuel/increasing air leans it.

And only 41 of those airplanes were built. https://en.wikipedia.org/wiki/Porsche_PFM_3200

And only four of them remain.

 

[brcase]

So all it needs is combustion, which requires three things: fuel, air, spark. (Oil has nothing to do with it.)

It's not getting one of those three things, so process of elimination:
- Air is an unlikely issue on the ground (unlike flight, with induction icing).
- Fuel is getting to the engine when you were able to flood it.
- So that makes it sound like spark. Which has been much mentioned here: mags, wires, plugs. Sounds like maintenance-induced failure, with at least one of those.

I agree it is likely Spark.
I have a friend that had mag fail the runup., he 5 minutes away from his home airport so decided to fly home to get it fixed. Decided to fuel it before taking it to hanger, He is an A&P so was going to fix it himself. Couldn't start it after fueling, the other mag had failed on shutdown. He may or may not have been known for taking more risks than the average pilot.

I had one where we doing a dual cross country flight. We shut down to discuss our next leg of the flight, didn't even get out of the airplane. Tried to start and it would just crank, Apparently the impulse coupling had failed on the Mag used for starting, The starting switch grounded the other mag, so we had no spark while cranking.

Brian
CFIIG/ASEL

 

[Magman]

Cheese: You are correct,. My bad. Closing the throttle will RICHEN and

not LEAN the mixture.

 

[Barrett50]

Glad it got solved, and was pretty easy. I still don't know if it starts on both or left, or if there was a change to the start procedure.

As for EFI, I think what's going to eventually come along is a dual fuel setup. There will be a mech fuel inj just as their is now, with the fuel spider and the fuel metering plate with the throttle plate. That will run independent of the new EFI system which will have its own injector, electronic controls and redundancy. On run up, the plane will have a mechanical selector valve for "E" and one position for "M". The pilot will runup on E and then switch to M and wait 10 seconds to test the backup injection system. The switch back to E for normal running. Should the EFI fail inflight the pilot first action is to turn the valve from E to M.

I doubt mags are going away either. Although there may be a single mag, and a single E ignition method with its own coil on plug setup. If their BSFC is .41, the gain over a LOP operated Conti at 65% power is almost nil. Long ago, I calculated my BSFC when running 60% power in cruise and I was getting .435 or so. If I did some work to the intake, and put larger exh valves in for lower adiabatic exh pressure I'm pretty sure I could hit .41 or very close to it with mech FI, matched injectors, and well setup mags.

As for the PFM, it was a disaster for Porsche and almost put them out of business. They never recovered the development money invested, as only less than 100 engines were ever produced. It was supposed to be light, simple, and common to the 3.2L 911 engine. By the end of development, there was almost zero commonality with the Porsche auto 3.2L engine. Running it at 5300RPM also made for such high piston speeds, the est TBO was going to be 800-1000 hours, or half of the TBO for the old Contisaurus. Porsche was going through a lot of pains back then, and lucky the water cooled transaxle car line pulled them out of their dire situation.

 

[WDD]

My mechanic noticed I was opening the mixture for too long. This morning, while watching me, he suggested I close the mixture as soon as the fuel flow peaks. POH says 3-5 seconds I was doing 6, now he recommends peak fuel flow. I tried peak fuel flow and the engine immediately started!

Thanks for posting the problem and the solution. I'm learning new things every day here. I've not flown a plane with FI, and not familiar with "closing mixture as fuel flow peaks" - heck, still not sure what that means. I'll have to dig into that a bit.

 

[MooneyDriver78]

Funny, I have to do 5 seconds or more if cold, but I open the throttle about 1/4 of the way as instructed by the POH, maybe full throttle it would take less time? Otherwise it takes a few seconds of cranking to get it started (Lycoming IO360). I like it to start in 1-3 blades .

 

[flyingcheesehead]

Thanks for posting the problem and the solution. I'm learning new things every day here. I've not flown a plane with FI, and not familiar with "closing mixture as fuel flow peaks" - heck, still not sure what that means. I'll have to dig into that a bit.

It's irrelevant to carbed airplanes, where you're probably priming with a manual priming pump. In a fuel injected airplane, you prime by turning the fuel pump on, pulling the mixture to idle cutoff to stop priming and then when the engine catches you shove the mixture back in so it keeps running.

And yes, there's a million little finicky details, asterisks, etc depending on what type of aircraft, engine, and conditions so this is not a comprehensive description.

 

[Gary Ward]

I got a 0-320 with a D mag that always starts quickly hot or cold.
I have never used the primer.
2 smooth strokes of the throttle is all it takes for a cold start. Single digits cold it gets 3.

Hot 1 stroke all it takes. Both mags are fired by the impulse coupler making it easy to start.

 

[Dan Thomas]

Funny, I have to do 5 seconds or more if cold, but I open the throttle about 1/4 of the way as instructed by the POH, maybe full throttle it would take less time? Otherwise it takes a few seconds of cranking to get it started (Lycoming IO360). I like it to start in 1-3 blades .

Opening the throttle will pump fuel in more quickly. The pump is pressurizing the fuel servo, and the throttle controls the servo to meter fuel appropriate to the throttle setting.

Fuel delivered more quickly will atomize better from the injectors. At idle, they only dribble, and starting on dribbled fuel, especially when the engine is cold, will be really poor.

Which is why your POH says 1/4 throttle.