Hard starting 67 M20F

[Tmarsha]

Folks, I now have about 10 hours in my newly purchased Mooney and have not figured out the best cold or hot starting method. I have followed the POH, throttle 1/2",pump on, mixture full rick for 5 seconds then lean, engage starter, when starts mixture slow in rich. Sometimes it will hit a few times, I will slowly move mixture in but does not start. I did notice what I thought was a 1/2" on the throttle was something less so I will start giving it a little more throttle and maybe that will make a difference. Plugs were recently cleaned at annual and look good. I'm interested in what works well for others, both cold & hot. I must confess I leave the pump on only until pressure increase stabilizes, then pump off. Maybe I should leave the pump on but I worry about too much fuel ?? I will look for earlier posts on this topic.

This Mooney should not be that difficult to start ?? Tks Tom

[larryb]

Congrats on your new plane. You'll get lots of advice on hot start. I do find the "dont touch anything" method works fine. That means, set the idle for 1000 rpm, shutdown with idle cutoff. Start the plane without touching anything, then push in mixture when it starts.

 

The one thing that I have not seen posted much is cold start. In my J, same engine, for cold start I prime with 5-10 seconds, depending on temperature, as soon as I get in the plane. Then I adjust the seat, put on seatbelt, headset, etc. Get organized. Crack the throttle about 1/4". After 30 seconds or a minute, I start the plane. This gives the fuel time to vaporize. I find the vaporization time is key. Without that, my starts are not always successful. With plenty of vaporization time, it starts in just a few blades almost always. Once I primed and left the airplane keys in the car. The vaporization time was probably 5 minutes. It started right up. Good luck.

 

One more thing, I find I have to briskly move mixture to rich after it catches. Slowly doesn't work so well for me.

 

Larry

[Tmarsha]

Thanks, I will give it a try and report back.  Tom 

[Lood]

Cold/ normal start:

Throttle open, mixture full rich, fuel pump on until fuel flow gauge needle just starts moving, normally between 4 - 7 seconds - not more than that. Then, throttle pulled back to 1/4" open and mixture pulled back a bit to about 3/4 OPEN. Using this method, my engine always starts after 3 - 4 blades. If I use the closed mixture method during a cold start, my engine takes forever before it starts, almost like in a hot start situation.

 

Hot start:

When you shut down and know that you have to start up again, set the idle between 1000 - 1200rpm and shut down pulling the mixture and leave everything as is. For the start, put your hand on the mixture and start swinging. After about 10 - 15 blades, the engine will start to cough and while keeping the starter engaged, slowly feed in some mixture and the engine will fire up. Sometimes, it will tend to die again, in which case I found a quick prime with the fuel pump, the best way to keep it running. If you don't catch it in time during a hot start, (this normally happens at a busy fuel bay) I just flood the engine and carry out the flooded start procedure.

 

Funny thing is that the same procedure will not work on all engines of the same model. Over time, you will sort out your own.

[PTK]

Congrats on your new plane. You'll get lots of advice on hot start. I do find the "dont touch anything" method works fine. That means, set the idle for 1000 rpm, shutdown with idle cutoff. Start the plane without touching anything, then push in mixture when it starts.

The one thing that I have not seen posted much is cold start. In my J, same engine, for cold start I prime with 5-10 seconds, depending on temperature, as soon as I get in the plane. Then I adjust the seat, put on seatbelt, headset, etc. Get organized. Crack the throttle about 1/4". After 30 seconds or a minute, I start the plane. This gives the fuel time to vaporize. I find the vaporization time is key. Without that, my starts are not always successful. With plenty of vaporization time, it starts in just a few blades almost always. Once I primed and left the airplane keys in the car. The vaporization time was probably 5 minutes. It started right up. Good luck.

One more thing, I find I have to briskly move mixture to rich after it catches. Slowly doesn't work so well for me.

Larry

Larry, have you tried not waiting 30 to 60 sec? I do essentially what you do for cold start except I don't wait that long at all. Throttle idle from last shutdown, mixture full rich, fuel pump on 8 Mississippi's, pump off, mixture idle cut off, engage starter, mixture in. Starts right up on the first blade. Once all cylinders start making EGT on the monitor lean aggressively.

[Glenn]

Cold Start

1. Throttle - open 1" or a little more
2. Mixture - Full Rich
3. Electric Pump - on until indication of Fuel Pressure, then off
4. Engage the starter

Hot Start  

1. Throttle - Wide open
2. Mixture - Closed
3. Engage Starter 
4. Enrich Mixture when the engine fires
5. Reduce throttle

 

I am on my third engine in my F model (over 29 years) and have never had these fail.

 

Good Luck.

[N601RX]

I use a procedure very close to Lood's and it cranks quickly.  I was having some problems getting it started 5 or 6 months ago.  Tuning up the shower of sparks fixed my hard starts.  Here is the post and video I made about it.

 

http://mooneyspace.com/topic/8019-hard-to-start/?hl=%2Bshower+%2Bsparks

[Tmarsha]

Interesting, never heard of "shower of sparks" ? Would like to hear more about that ? I think once I try the different suggestions and the one that works best for my engine, I will be good to go. I will report back once I get it figured out. Thanks Tom

[N601RX]

The shower of sparks is what fires the mag while the engine is being turned over slowly by the starter.  Once it starts and comes up to idle speed then the mags are turning fast enough to produce their own spark.  Newer models use impulse couplings for starting.

[BigTex]

Tom - If these techniques don't work, you might want to check your plugs to see how they look.  Also, check how many hours you have on your mags.  If you're getting close to the 500 hour mark, you might want to have them IRAN'd.

 

I never had much of an issue starting but every once in awhile it got cranky on me... especially after setting for a couple of weeks.  So I went scorch earth and had the Mag's IRAN'd and fine wire plugs installed... now the engine take maybe 1/4 turn to fire up.

[Super Dave]

I've also had poor results with the POH's cold start procedure on my 76F, so I've switched to the procedure outlined in the Lycoming Operators Manual. In summary:

Boost pump on

Throttle wide open

Mixture full rich

When fuel pressure stabilizes (about 2 seconds in my plane)...

Throttle closed

Mixture idle cut off

Boost pump off

Throttle cracked open

Engage starter and mixture goes full forward as engine starts.

The lycoming manual actually calls for the throttle to go to 1/4 travel just prior to cranking, but I've found that just cracking it results in a nice gentle start of about 800 RPM that slowly comes up to 1000RPM as the engine warms. No immediate blast to 1200RPM on a cold engine, and no jockying back and forth between mixture and throttle. I also like the procedure because it puts less time on the boost pump.

BTW Don Maxwell has a good article on Shower of Sparks here

http://www.donmaxwell.com/publications/publications.htm

[Bob_Belville]

Wow, a lot of methods, reminds me of all the conflicting "only way" to plant tomatoes advice I've heard over the years.

 

Super Dave's simple cold start method makes complete sense when you understand what the engine needs to fire: spark and a combustible air/fuel vapor mixture.

 

By opening the throttle full with mixture full the boost pump can provide fuel to the injectors. Most common recommendation is 5 seconds. Some suggest a little longer when ambient is cold, less when it's hot. I am not sure that matters much.

 

Then, with boost pump off, mixture in cut off position to prevent flooding and throttle @ ~ 1000-1200 position, cranking the starter for a very few seconds should present spark to the cylinders as the fuel/air ratio gradually decreases and if the mags and plugs are healthy and the timing is reasonable close to 20 BTDC (or 25 for some engines) the engine has to fire. At that point you should have plenty of time to gradually advance the mixture which is where your right hand has been resting while you engage starter.

 

With mixture closed you should not be able to flood the engine even if the electrical components are not up to snuff.

[DrBill]

Cold Start (found somewhere on the web).. works flawless for me and an "F" owner on airport.

Throttle and mixture full rich.  

Electric pump on for 6-7 seconds (NO MORE).

Throttle at 1000 rpm position (about 1/4 in in).

Mixture at CUTOFF.

Start

When catches, mixture full rich....

 

Hot Starts...

KEY:  Mixture to cutoff with ideling at 1000 rpm and then LEAVE ALL ALONE>

Get in , Master -on, DONT TOUCH ANYTHING ELSE

Clear and start... When catches advance mixture.

 

Here's a good article I read before purchase:

http://www.mooneypilots.com/mapalog/HOT%20STARTS.htm

 

 

BILL

[N201MKTurbo]

I am doing my annual this weekend at KCHD hanger J1 come by and we can talk about m20fs. I owned one for 19 years. I can tell you how to start it in any situation.

[Steve65E-NC]

You do not mention your Starter Type. I never had any problem with cold-starts on my 65E. But, hot-starts were always more or less of a problem. I experimented with every technique. I often just went ahead and flooded it on purpose and did a full throttle, flood-clear, start (be ready on the mixture and throttle). Finally, I just wore out my old starter and it came apart in place. I did some research and installed a Sky-Tec 149-NL. It spins the engine over so fast that hot starts are just no longer a problem no matter. I think many others have had similar experience. The starter I purchased has a shear pin that can be sheared by back-fire (I carry spare pins, but starter removal would be required - never heard of it happening to anyone).

However, if you have cold start problems sounds like something else may also be a problem. I might start by having someone disassemble the key switch and clean all contacts (careful, lots of little parts but logical arrangement).

[Mooneymite]

The shower of sparks is what fires the mag while the engine is being turned over slowly by the starter.  Once it starts and comes up to idle speed then the mags are turning fast enough to produce their own spark.  Newer models use impulse couplings for starting.

 

When I had problems with my Bendix shower of sparks box, it turned out to be a (very inexpensive) capacitor that was bad and kept causing the points to burn.  It was a headache to track down, but the fix was simple/easy/cheap.

 

Additional info here:  http://www.donmaxwell.com/publications/MAPA_TEXT/Shower%20of%20Sparks/Shower%20of%20Sparks.htm

[HRM]

Mooneys are not hard to start--unless there is something wrong with the engine. Didn't you fret over this plane? I'd take it back to whoever sold it to you or signed off on it.

Need not be anything expensive.

[jnisley]

I've never had a problem with cold starts but I struggled with hot starts until I adopted the method described below and it has never failed me whether I restarted 5 minutes or 2 hours after shutdown.

Cold start

Throttle 1000-1200 rpm

Boost pump on

Mixture full rich 8-10 seconds, mixture off, smoothly advance mixture to full after engine fires.

Hot start

Throttle 1000-1200 rpm

Boost pump on

Mixture full rich 1-2 seconds, mixture off, smoothly advance mixture to full after engine fires.

[ncdmtb]

Hot Start:

I have a 64 M20E and I use the following procedure.

the trick for the hot start is the shutdown. I go to 1100 RPM then pull mixture and shut off. Don't touch the throttle.

When you start, dont touch throttle. Leave as is, engage starter and full mixture. Once the engine is running then use throttle.

I have been flying my plane for about 5 months and not have had any issues with hot starts.

-Nick

[OR75]

Hot start: as mentioned above, leave all controls alone and crank. It will start 4 out of 5 times. If it does not, ... Then the fun or aggravating part get started. It will take a toll on the battery and starter.

Does anyone know why hot start are such a pain ? May be understanding will help find and answer.

[N201MKTurbo]

Hot starts are a pain because the fuel injection lines are above the cylinders. When the engine is shut down the heat from the cylinders boils the fuel in the lines and forces it out into the cylinders, so all the cylinders are flooded, especially the ones with the exhaust valves open. It also means all the fuel injuction lines are empty, so it takes a bit for fuel to refill the lines which probably helps the situation.

 

I always assume the engine is flooded for eight hours after I shut it down. For a day after that I find that the best way to start it is just set the mixture to full rich throttle to its happy spot and crank, no priming. Don't run the fuel pump unless it has been a few days sense you ran the engine.

 

Lycoming IO-360s are always flooded!

[BigTex]

Too bad you guys can't upgrade to a carbureted engine!

[carusoam]

Fuel evaporation rates make all starts a balancing act. The hot engine readily evaporates fuel, the <20f engine doesn't want to evaporate fuel at all... Fuel evaporation also takes time. More cold= more time.

(1) Figure out the state of your engine. (Cold, warm or hot)

(2) Figure out what the engine needs. (no fuel, some fuel, lot's of fuel)

(3) Determine how to give your engine what it needs. (pull mixture out, do nothing, fuel pump for a few seconds, pump throttle 10 times)

Take notes on what works for you in each of these situations. Following your notes should be a pretty reliable way to make good starts.

There are special cases such as avoiding evaporation in fuel lines in Conitental engines. The fuel system plumbing allows for warmed fuel to be returned to the tank. (if you follow the instructions).

Modern automobile engines are equally hard to start for the same reasons. But, they also have computers to determine the status and computer controlled fuel injection to adjust fuel flow.

Compounding the issues is the low partial pressure of 100LL fuel. It doesn't like to evaporate as much as mogas, especially at temps below 20f.

How does that sound? Did I answer the question? Or did I spout some unneeded details, just to write something on a Sunday Morning?

Best regards,

-a-

[OR75]

I read somewhere that you can refill the fuel lines by running the pump with throttle all the way open and the mixture full rich. That circulates colder fuel in the lines. But that would applies only to continental engines. Not mechanically inclined to know exactly why

If the fuel get into the cylinders, it should evaporate pretty quick. So not sure how the lycoming could always be flooded.

[carusoam]

Fuel to air ratio is a relatively narrow window for the engine to run. Sending fuel to the cylinders can result in too much fuel being in there to run. And continuing to evaporate for a while

The challenge is knowing if there is too much or too little and then make the adjustment...

This is why some people flood it, than use the flood start technique....

If it is really cold outside, a C may use so much fuel, the pilot may fear a fire, while fuel is draining from the carb overflow...and pouring down onto the tire...

OR,

Check the details in the POH on that... Mine says throttle open, mixture cut-off, pump on...this will recirculate fuel back to the tank...

Then throttle to idle, mixture to rich, then start.

Most Lycomings do not use the return lines, thus the procedures are slightly different...

Best regards,

-a-