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Hello everyone,

I'm new to this forum (also knew to airplane ownership). Since I bought my 77' M20J a month ago I have been having problems with starting it. When I follow the POH, the engine doesn't start on my first attempt. After letting the starter cool, I cycle the throttle and mixture and it usually starts on the second or third attempt.

Most of my flight experience has been in CG helicopters - with digital engine controls, and I've never had starting problems. My problem might just be my limited experience with GA aircraft. These are the key steps I follow in starting my Mooney. Can any of you give me advice? Am I doing something wrong?

1. Electric boost pump ON (1-2 seconds, to establish fuel pressure)

2. Mixture full forward for 3-5 seconds. (when I do this, the fuel pressure drops) then IDLE CUTOFF

3. Throttle 1/4 forward

4. Engage starter

5. Once the engine starts, Mixture slowly to full rich

6. Throttle - 1000-1200 RPM

Thanks,

Roger

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Welcome Roger!

This is my cold start procedure in my J:

Fuel selector fullest tank, mixture full rich, fuel pump on for 8 -12 sec then off, mixture ICO, don't touch throttle...its already at ~1000 RPM from previous shutdown, wait a few sconds, turn key. Ready with mixture rich once she fires. Don't need full rich mixture. Only as much mixture as needed. Not full rich. Lean brutally for ground ops.

Fires up in one blade most of the time. 

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I have a 78 J. If you have an issue, try keeping the boost pump engaged a little longer. Throttle about 1/4” in, mixture rich for boost. I count to 5 really slowly pull mixture to idle and attempt start. As soon as it turns over slowly go to about 1/2” from full rich as engine comes to life. If not successful within a few a few turns back to full rich, boost once more for 2-3 seconds and back to idle to give it another go. Will start like a charm. Every engine is a little different so you have to find what works for you.

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(Not to rain on your parade, Roger...)

 

Welcome aboard Roger...

You might want to consider some transition training to go with that new ownership experience...

Aside from starting the engine, there are a few other quirks that are better to be known before hand, then trying to figure out in flight...

There is also a search feature here... you can learn a bunch of things...

there is plenty written about hot starts... some written about really cold starts... I don’t remember any covering normal starts...

difficult normal starts are usually connected with something not working properly...

Getting transition training may be a way to have somebody knowledgeable with a Mooney help you identify what isn’t working properly...

There is a lot to know regarding ownership and flying old planes...

Transition Training isn’t just for newbies....

gruff old PP thoughts only, not a CFI...

Best regards,

-a-

 

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Hello everyone,
I'm new to this forum (also knew to airplane ownership). Since I bought my 77' M20J a month ago I have been having problems with starting it. When I follow the POH, the engine doesn't start on my first attempt. After letting the starter cool, I cycle the throttle and mixture and it usually starts on the second or third attempt.
Most of my flight experience has been in CG helicopters - with digital engine controls, and I've never had starting problems. My problem might just be my limited experience with GA aircraft. These are the key steps I follow in starting my Mooney. Can any of you give me advice? Am I doing something wrong?
1. Electric boost pump ON (1-2 seconds, to establish fuel pressure)
2. Mixture full forward for 3-5 seconds. (when I do this, the fuel pressure drops) then IDLE CUTOFF
3. Throttle 1/4 forward
4. Engage starter
5. Once the engine starts, Mixture slowly to full rich
6. Throttle - 1000-1200 RPM
Thanks,
Roger


Just to be clear, are you boosting with the mixture to idle cutoff? That is more than likely your issue. You should boost with mixture full rich and then go to idle cutoff to start. With the method you are describing there is no fuel getting to the engine when you boost.


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1 hour ago, PTK said:

Fuel selector fullest tank, mixture full rich, fuel pump on for 8 -12 sec then off, mixture ICO, don't touch throttle...its already at ~1000 RPM from previous shutdown, wait a few sconds, turn key. Ready with mixture rich once she fires. Don't need full rich mixture. Only as much mixture as needed. Not full rich. Lean brutally for ground ops.

+ 1... except I generally pull throttle closed on shutdown. My second step in the above is to add 1/4" of throttle. Fires up every time...

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1 hour ago, CG Roger said:

2. Mixture full forward for 3-5 seconds. (when I do this, the fuel pressure drops) then IDLE CUTOFF

Roger, try 6 seconds, exactly. Works for me every time, even with a marginal battery.

Of course, I fly an E and they are super.

If it isn't starting within a few blades, then spark, fuel and air--that's it. Very simple. Else, hie thee to a wizened Mooney A&P.

Edited by HRM
Capitalization.
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Mixture full rich, then boost pump, then cutoff. I do 3-5 seconds boost in summer and 5-7 seconds in winter.  Don't touch the throttle.

Main thing for the cold start is after boost pump and going to idle cutoff then wait about 15 seconds in summer and 30 seconds or more in winter. This gives fuel time to vaporize and it starts right away. 

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2 hours ago, CG Roger said:

Hello everyone,

I'm new to this forum (also knew to airplane ownership). Since I bought my 77' M20J a month ago I have been having problems with starting it. When I follow the POH, the engine doesn't start on my first attempt. After letting the starter cool, I cycle the throttle and mixture and it usually starts on the second or third attempt.

Most of my flight experience has been in CG helicopters - with digital engine controls, and I've never had starting problems. My problem might just be my limited experience with GA aircraft. These are the key steps I follow in starting my Mooney. Can any of you give me advice? Am I doing something wrong?

1. Electric boost pump ON (1-2 seconds, to establish fuel pressure)

2. Mixture full forward for 3-5 seconds. (when I do this, the fuel pressure drops) then IDLE CUTOFF

3. Throttle 1/4 forward

4. Engage starter

5. Once the engine starts, Mixture slowly to full rich

6. Throttle - 1000-1200 RPM

Thanks,

Roger

if youre completely leaned out while the boost pump is on, no fuel is going to the engine.

My guess, thats your problem. the way you're starting it, is exactly the same way than if you just

started it without boost pump. 

My start procedure for a cessna that had the same engine as your J:

Mixture Full rich 
boost pump for at least 5 seconds.
Mixture Lean
Throttle in 1/8 - 1/4 of an inch
Start engine
once it catches, mixture full rich.

started like a charm everytime.

Edited by Niko182
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10 hours ago, carusoam said:

(Not to rain on your parade, Roger...)

 

Welcome aboard Roger...

You might want to consider some transition training to go with that new ownership experience...

Aside from starting the engine, there are a few other quirks that are better to be known before hand, then trying to figure out in flight...

There is also a search feature here... you can learn a bunch of things...

there is plenty written about hot starts... some written about really cold starts... I don’t remember any covering normal starts...

difficult normal starts are usually connected with something not working properly...

Getting transition training may be a way to have somebody knowledgeable with a Mooney help you identify what isn’t working properly...

There is a lot to know regarding ownership and flying old planes...

Transition Training isn’t just for newbies....

gruff old PP thoughts only, not a CFI...

Best regards,

-a-

 

-a-

I appreciate your thoughts. I did receive 4 hours ground and 3 hours flight transition training from a CFI when I first got the plane. But we focused more on the in flight performance of the plane then on basic GA issues like starting a piston engine.

I have also been doing lots of reading on this forum to enhance my knowledge more.

-Roger

 

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Roger,

I’m glad you were able to share your transition training details...

Getting the fuel mixture right for starting gets easier over time.

It can help to have things like...

  • fuel flow indicator.
  • Outside air temp gauge.
  • CHT gauge.

An interesting comparison... the IO550 requires the throttle to be full in, with the mixture full in, to get good consistent FF for delivering fuel  to the engine...  the fuel lines are empty so it may take some time before counting the Mississippis...

Nobody likes having the throttle control all the way in prior to start... a subtle hint of how strong your memory skills are...

With cold OAT it may help to keep the boost pump on low for a minute or two...while things warm up... (IO550)

 

now read up on the hot start technique.  There is a great video made by a Mooney guru posted around here somewhere....

Best regards,

-a-

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@CG Roger welcome to the forum - fear not, all questions are valid (and mostly met with valuable insight)  there are topics here that will bring lively debate - others will bring experience and wisdom 

If ya think cold starts was something wait till you ask about hot starts :lol: and venture carefully into lean o peak...... 

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[mention=17201]CG Roger[/mention] welcome to the forum - fear not, all questions are valid (and mostly met with valuable insight)  there are topics here that will bring lively debate - others will bring experience and wisdom 
If ya think cold starts was something wait till you ask about hot starts :lol: and venture carefully into lean o peak...... 

You mean everyone doesn’t run LOP? Hot starts are a piece of cake. Just don’t touch anything and start er up! Love this place.


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Roger,

There are cold starts, hot starts, and warm starts.  For my '78 J:

Cold start:

Throttle 1/4" to 1/2" forward, mixture full rich, boost pump for 5 seconds, boost pump off, mixture cutoff, crank, when it catches.. mixture smoothly about half way to full rich, throttle back to 1000 RPM.  If it doesn't start within a few seconds, start over but only use about 2 or 3 seconds of boost pump.

Hot start:

Throttle 1/4" to 1/2" forward, mixture cutoff, crank, when it catches.. mixture smoothly about half way to full rich, throttle back to 1000 RPM.  If it doesn't start, proceed to warm start.

Warm start:

Same as cold start except only use the boost pump long enough to establish fuel pressure.  That's usually only a second or two at the most.

Have fun.

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14 hours ago, CG Roger said:

Hello everyone,

I'm new to this forum (also knew to airplane ownership). Since I bought my 77' M20J a month ago I have been having problems with starting it. When I follow the POH, the engine doesn't start on my first attempt. After letting the starter cool, I cycle the throttle and mixture and it usually starts on the second or third attempt.

Most of my flight experience has been in CG helicopters - with digital engine controls, and I've never had starting problems. My problem might just be my limited experience with GA aircraft. These are the key steps I follow in starting my Mooney. Can any of you give me advice? Am I doing something wrong?

1. Electric boost pump ON (1-2 seconds, to establish fuel pressure)

2. Mixture full forward for 3-5 seconds. (when I do this, the fuel pressure drops) then IDLE CUTOFF

3. Throttle 1/4 forward

4. Engage starter

5. Once the engine starts, Mixture slowly to full rich

6. Throttle - 1000-1200 RPM

Thanks,

Roger

Just remember to wait 30-45 seconds between 3 and 4.  You need to give the fuel some time to vaporize.  I use the time to set up the cockpit.

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15 hours ago, CG Roger said:

2. Mixture full forward for 3-5 seconds. (when I do this, the fuel pressure drops) then IDLE CUTOFF

3. Throttle 1/4 forward

Wait, your fuel pressure drops when you move to full rich?  I don't think that should happen.  There might be some hiccups as you clear out the fuel lines, but the fuel pressure should rapidly go to about 25-27 psi and stay there when you turn the pump on.  The fuel flow is tiny when you prime the engine, so the fuel pressure should not drop significantly when you move the mixture forwards.

Realistically, there should be no difference between turning on the fuel pump first vs mixture forward first as long as you run it with both on consistently about 5 seconds (although the POH does specify mixture forward first).

Also, the throttle position should be set BEFORE running the fuel pump and mixture forwards.

FWIW, I think the amount of throttle you use on cold starts isn't too important, as long as it's enough.  If you're unfamiliar with the engine, I'd suggest starting with about 3/4" of throttle or more, and then working your way back to find the minimum throttle you need.  You won't flood the engine, but if you have too much fuel, it'll just take a few more cranks before catching (just be ready to reduce the throttle as the engine starts).  As you reduce the amount of throttle for cold starts, it'll take fewer and fewer turns before catching, until you have too little, then it won't start at all.  If you start with too little throttle and try to work your way up, it's harder to learn anything on the second attempt, because once you turn on the fuel pump, you're starting conditions are no longer the same, since you've now pressurized your fuel lines

Edit:  Ahh, I see, you stopped the fuel pump before moving the mixture forwards, that's why your fuel pressure drops.  Have you reviewed your POH on cold starts?  Mine ('86 M20J) says:

Throttle - 1/4 open
Propeller - HIGH RPM
Mixture - Full Forward (RICH)
Master switch - ON
Annunciator lights - Test
Fuel Boost Pump - On to establish pressure, then off
Mixture - Idle cutoff

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8 hours ago, jaylw314 said:

Edit:  Ahh, I see, you stopped the fuel pump before moving the mixture forwards, that's why your fuel pressure drops.  Have you reviewed your POH on cold starts?  Mine ('86 M20J) says:

 

I did review the POH for cold starts. It just wasn't clear to me that the pump should stay on when I advance the mixture to rich. They were listed as two separate steps, I read it as complete the first one (pump on momentarily) then move the mixture to rich. I see the error in my ways, I'm looking forward to trying the next cold start.

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Some of you use 1/4 inch of throttle for boost pump on; some (including me) use 1/4 throttle.  My POH says 1/4. When I first got ‘84L I used 1/4 inch and it was always hard to start.  1/4 and 5 to 6 seconds of boost fires it up immediately 

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15 hours ago, CG Roger said:

I did review the POH for cold starts. It just wasn't clear to me that the pump should stay on when I advance the mixture to rich. They were listed as two separate steps, I read it as complete the first one (pump on momentarily) then move the mixture to rich. I see the error in my ways, I'm looking forward to trying the next cold start.

That's why I mentioned my POH, which says mixture to rich BEFORE turning on the boost pump.  Does anyone know when they changed that?

Here's to an easy start on your next flight!

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You will be able to start with your method but it will require the starter turning the crank, accessory gear, and engine driven fuel pump over a lot of blades with the mixture open a bit to get fuel to the cylinders and you risk running down a battery or melting a starter ;-)

When baby bottling one time I watched how much fuel dribbled in and how “liquid” it is when it does so during engine priming.  Definitely count to 15-30 to let it vaporize. 

 

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On 6/4/2018 at 8:57 PM, CG Roger said:

Hello everyone,

I'm new to this forum (also knew to airplane ownership). Since I bought my 77' M20J a month ago I have been having problems with starting it. When I follow the POH, the engine doesn't start on my first attempt. After letting the starter cool, I cycle the throttle and mixture and it usually starts on the second or third attempt.

Most of my flight experience has been in CG helicopters - with digital engine controls, and I've never had starting problems. My problem might just be my limited experience with GA aircraft. These are the key steps I follow in starting my Mooney. Can any of you give me advice? Am I doing something wrong?

1. Electric boost pump ON (1-2 seconds, to establish fuel pressure)

2. Mixture full forward for 3-5 seconds. (when I do this, the fuel pressure drops) then IDLE CUTOFF

3. Throttle 1/4 forward

4. Engage starter

5. Once the engine starts, Mixture slowly to full rich

6. Throttle - 1000-1200 RPM

Thanks,

Roger

Not enough fuel is being delivered to the engine.  Throttle wide open, mixture full rich, pump on until flow or pressure, 2-3 seconds, throttle to idle, engage starter.

Remember back in flight school, a few strokes of the engine primer, was all it took to start.

Clarence 

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